ISO 23903:2021

INTERNATIONAL ISO
STANDARD 23903
First edition
2021-04
Health informatics — Interoperability
and integration reference architecture
– Model and framework
Informatique de santé — Architecture de référence d'interopérabilité
et d'intégration — Modèle et cadre
Reference number
ISO 23903:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23903:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 23903:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 5
5 Overview on standard system architecture. 5
6 Interoperability and Integration Reference Architecture for ICT Supported Systems .6
6.1 Interoperability and Integration Reference Architecture domains and granularity levels . 6
6.2 Interoperability and Integration Reference Architecture model for ICT supported
systems . 7
6.3 Interoperability and Integration Reference Architecture framework . 8
6.3.1 Basic requirements . 8
6.3.2 Management of relationships in the Interoperability and Integration
Reference Architecture . 9
6.3.3 Business process modelling using the Interoperability and Integration
Reference Architecture . 9
Annex A (informative) Cross-domain interoperability for security and privacy aware EHR
communication .11
Annex B (informative) Interoperability between different communication standards .13
Annex C (informative) Integration of Standards in ISO 12967 (all parts) .15
Annex D (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach in ISO 13972.18
Annex E (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach for the Representation and Harmonization of Alternative
Reference Architectures .19
Bibliography .21
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ISO 23903:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 251, Health
informatics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

Introduction
0.1  Preface
This document supports the integration of a) specifications from different domains with their specific
methodologies, terminologies and ontologies including specific specification style as well as b) systems
based on those specifications. Enabling the use-case-specific identification and consistent, formal
representation including constraints of necessary components with their specific concepts and their
relationships, this document facilitates the deployment of existing standards and systems, the analysis
and improvement of specifications under revision as well as the design of new projects.
This document provides an overview of the Interoperability and Integration Reference Architecture
[1][2]
(first introduced in the 1990s as the Generic Component Model – GCM ), providing scope, justification
and explanation of key concepts and the resulting model and framework. It contains explanatory
material on how this Interoperability and Integration Reference Architecture is interpreted and applied
by its users, who might include standards writers and architects of interoperable systems, but also
systems integrators.
The ongoing organizational, methodological and technological paradigm changes in health and
social care result in health systems transformation toward P5 (personalized, preventive, predictive,
participative precision) systems medicine as fully distributed, highly dynamic, strongly integrated,
multi-disciplinary (or multi-domain) intelligent ecosystems, comprising both structured systems,
[3]
communities governed by rules, and combinations thereof .
0.2  Interoperability levels
Interoperability (see 3.16) has evolved during the last 30 years from structured messaging (e.g. EDI,
1) 2) [4]
HL7® messaging) over sharing concepts [e.g. openEHR® Archetypes, ISO 13940 (system of
concepts to support continuity of care)] – both representing the data/information exchange paradigm
– to cooperation at application level (e.g. Web services). All those solutions focus on information and
communication technologies (ICT) systems interoperability using ICT terminologies and ontologies
for representing data, information, or even concepts and knowledge, thereby distinguishing the three
interoperability levels: a) foundational, b) structural, and c) semantic interoperability.
On the move towards digital health, ICT systems get more closely integrated in the real world business
process. This move requires supporting advanced, knowledge-level and business process focused
interoperability between all principals acting in those ecosystems such as persons, organizations,
devices, applications, components, or objects to achieve the common business objectives. As knowledge,
methodologies and terminologies of the domains involved in the business case and represented through
those domains’ ontologies, but also individual contexts, abilities and capabilities are highly different,
they must be shared and adapted in advance or dynamically at runtime, enabling adequate cooperation
[5]
of actors and systems involved. Table 1 summarizes the different interoperability levels .
1) HL7 is a registered trademark of Health Level Seven International. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
2) openEHR is a registered trademark of the openEHR Foundation. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
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ISO 23903:2021(E)

Table 1 — Interoperability levels
Information Perspective Organization Perspective
Interoperability
Instances Interoperability Level
Level
Technical Technical plug&play, signal & protocol com- Light-weight interactions
patibility
Structural Simple EDI, envelopes Data sharing
Syntactic Messages and clinical documents with agreed Information sharing
vocabulary
Semantic Advanced messaging with common information Knowledge sharing at IT concept level in
models and terminologies computer-parsable form
Coordination
O rg a n iza t i o n / Common business process Knowledge sharing at business concept level
Service
Agreed service function level cooperation
Knowledge based Multi-domain processes Knowledge sharing at domain level
Cross-domain cooperation
Skills based Individual engagement in multiple domains Knowledge sharing in individual context
Moderated end-user collaboration
0.3  Motivation for the Interoperability and Integration Reference Architecture
Meeting the objectives of improving safety, quality and efficiency of care with ICT support requires
advancing interoperability between computer systems towards a business-process-specific co-
operation of actors representing the different domains participating in the business case. For that
purpose, the agreed domain knowledge, but also the individual and shared context (language, education,
skills, experiences, psychological, social, occupational, environmental aspects, etc.), need to be
represented correctly and formally for integration with the ICT system as part of the business system.
As the domain experts involved describe specific aspects of that business system in their own specific
contexts and using specific terminologies and ontologies, methodologies and frameworks, the resulting
informational representations are often quite inconsistent, requiring a peer-to-peer interoperability
adaptation process. Adapting existing standardized informational representations of domain-specific
use cases to changing contexts or contexts including multiple domains requires another common
harmonized informational representation, resulting in permanent revisions of specifications.
Modelling systems for multi-domain interoperability requires the advancement from the data model,
information model, and ICT domain knowledge perspective to the knowledge perspective of the
[6]
business domains . For achieving the latter, the relevant stakeholders are responsible to define the
provided view of the model as well as the way of structuring and naming the concepts of the problem
space. First capturing key concepts and key relations at a high level of abstraction, different abstraction
levels can be used iteratively. Thereby, the first iteration is performed in a top-down manner to
guarantee the conceptual integrity of the model. This demands meeting design principles such as
[7] [8]
orthogonality, generality, parsimony, and propriety. ISO 30401 defines the requirements for
knowledge management systems in organizations to meet business objectives.
It is impossible to represent the highly complex, highly dynamic, multi-disciplinary/multi-domain
healthcare system by one domain‘s terminology/ontology or – even worse for the reasons mentioned
right before - by exclusively using ICT ontologies and ICT specific representation styles.
The alternative is an abstract, domain-independent representation of systems using Universal Type
[9]
Theory and corresponding logics. The mathematical concept representation using a Meta Reference
[9]
Architecture according to the formal theory of the Barendregt Cube with Parameters in combination
with systems engineering methodologies allows representing any system architecturally (i.e. the
system’s components, their functions and internal as well as external relations) by generically describing
its composition/decomposition and behaviour from the perspectives of all domains of relevance in a
specific business case. A third dimension describes the system’s development process such as evolution
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ISO 23903:2021(E)

for living systems, manufacturing for technical systems, or a software development process, resulting
in a generic system model or Generic Reference Architecture presented in Figure 1. Details regarding
the dimensions of the model are explained in Clause 5 and Clause 6.
Figure 1 — Generic Reference Architecture model
To represent advanced interoperability and integration settings, different domain-specific
representations are linked to the same real world component. Therefore, an abstract and generic
reference architecture is needed which is able to represent any aspect or domain of interest. For
correctly and formally representing the concepts and relations of the domain-specific subsystems
involved in that business case, those subsystems are represented by their corresponding approved
domain ontologies, resulting in a system-theoretical, architecture-centric, top-level ontology driven
[10][11]
approach . Requirements for top level ontologies are specified in ISO 21838 (all parts). Health
3)
domain ontologies are SNOMED-CT® or specific ontologies such as the Open Biomedical Ontologies
[12] [13]
(OBO), including the Gene Ontology, maintained by the OBO Foundry .
As we can consistently model and compute only systems of reasonable complexity, the Generic Reference
Architecture model (Figure 1) can be used recursively at different granularity levels, so representing,
e.g. the continuum of real-world systems from elementary particles to the universe. The concepts of
the system’s components and their relations are represented in appropriate expressions in natural or
formal languages up to the basic level of primitives. The system analysis or design needs to address
partial systems when considering higher granularity levels of the system in question.
0.4  Technical approach
A system is a composition of interrelated components, ordered to accomplish a specific function or a
set of functions. Systems can be decomposed into subsystems or composed to form super-systems.
There are constructive or structural and behavioural or functional aspects of systems. According to
[14]
IEEE 1471, the architecture of a system is the fundamental organization of that system embodied in
its components, their relationships to each other and to the environment, and the principles guiding its
design and evolution. Rules for selecting and constraining components and functions as well as relations
according to a business case are called policies. Policies define the intended behaviour of a system. For
living systems, factors such as homeostasis, with the attributes of self-organization and self-regulation
as well as growth and development, reproduction, with the associated heredity (structure preservation)
and mutation (structural change), and higher development through selection of best-adapted variants
out of a large number make the description of living systems more complicated than that of technical
[15]
systems .
3) SNOMED CT is the registered trademark of the International Health Terminology Standards Development
Organisation (IHTSDO). This information is given for the convenience of users of this document and does not
constitute an endorsement by ISO of the product named.
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ISO 23903:2021(E)

In the 1970s and 1980s, a data level interoperability approach was developed by defining the
application and technology agnostic standard data exchange format EDI (electronic data interchange)
in order to transform proprietary data formats into the standard data format and vice versa.
[16]
Thus International Standards arose such as ISO 9735 (EDIFACT), or its healthcare-specific
[17]
pendant ISO/HL7 27931:2009, an application protocol for electronic data exchange in healthcare
environments. This document defines a generic system architecture for knowledge level interoperability.
It allows consistently transforming and interrelating any domain specific subsystem’s structure and
behaviour (e.g. domain specific standards and specifications) by ontologically representing its concepts
and relationships at the real world system component’s level of granularity in the abstract generic
component system. In other words, the domain specific subsystem (e.g. a domain specific standard or
specification) is re-engineered using the Interoperability and Integration Reference Architecture, by
that way providing a standardized interface to that specification. In this way, the methodology offered
in this document maps between domain specific or proprietary systems and their representation as
specification or domain specific standard by transforming them into a standard system architecture
and vice versa. Annex A demonstrates the integration of two domain specific standards by reengineering
[18]
the ISO 13606-1 Reference Model and the HL7® Composite Security and Privacy Domain Analysis
[19]
Model and combining them in an Interoperability and Integration Reference Architecture model
instance. Annex B demonstrates the integration of different communication standards by reengineering
4) 4)
HL7 v3® methodology and creating an adequate HL7 v2® methodology and transforming them into
an Interoperability and Integration Reference Architecture instance. In this way, the Interoperability
and Integration Reference Architecture supports the mutual transformation of those communications
standards for the sake of interoperability of existing solutions. For ontologically representing the
[20]
models, the Communication Standards Ontology (CSO) has been used. Figure 2 correspondingly
presents this standard’s interoperability approach. Annex C demonstrates the integration of different
[21]
standards in the light of ISO 12967(all parts) , while Annex D presents the approach in context of
[22]
ISO 13972 . Finally, Annex E demonstrates the deployment of this document’s Interoperability and
Integration Reference Architecture for the representation and harmonization of alternative reference
architectures.
4) HL7 v3 and HL7 v2 are registered trademarks of Health Level Seven International. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of the products named.
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ISO 23903:2021(E)

Figure 2 — Overview of this document’s interoperability approach
Bound to the GCM Framework, inter-domain relationships need to happen at the same level of
[23]
granularity . To get there, intra-domain specializations/generalizations are performed.
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INTERNATIONAL STANDARD ISO 23903:2021(E)
Health informatics — Interoperability and integration
reference architecture – Model and framework
1 Scope
This document enables the advancement of interoperability from the data/information exchange
paradigm to knowledge sharing at decreasing level of abstraction, starting at IT concept level (semantic
coordination) through business domain concept level (agreed service function level cooperation),
domain level (cross-domain cooperation) up to individual context (skills-based end-user collaboration).
The document defines a model and framework for a harmonized representation of existing or intended
systems with a specific focus on ICT-supported business systems. The Interoperability and Integration
Reference Architecture supports ontology harmonization or knowledge harmonization to enable
interoperability between, and integration of, systems, standards and solutions at any level of complexity
without the demand for continuously adapting/revising those specifications. The approach can be
used for analysing, designing, integrating, and running any type of systems. For realizing advanced
interoperability, flexible, scalable, business-controlled, adaptive, knowledge-based, intelligent health
and social ecosystems need to follow a systems-oriented, architecture-centric, ontology-based and
policy-driven approach.
The languages for representing the different views on systems such as ontology languages like
[24] [25] [26]
Common Logic (CL) (ISO/IEC 24707 ) and Web Ontology Language (OWL) – specifically OWL 2
5)
(World Wide Web Consortium (W3C® ), languages for modeling and integrating business processes
6)
like Business Process Modeling Language (BPML) (OMG® ), but also OMG’s Unified Modeling
[27]
Language (UML, also specified as ISO/IEC 19505 ) based representation styles for the different
ISO/IEC 10746 (all parts) views are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10746 (all parts), Information technology — Open distributed processing — Reference model
ISO 22600 (all parts), Health informatics — Privilege management and access control
ISO/IEC 21838 (all parts), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
5) W3C is a registered trademark of the World Wide Web Consortium. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
6) OMG is a registered trademark of The Object Management Group®. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
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ISO 23903:2021(E)

3.1
architecture
set of rules to define the structure of a system (3.25) and the interrelationships between its parts
[SOURCE: ISO/IEC 10746-2:2009, 6.6, modified — "(of a system)" removed from term.]
3.2
axiom
statement that is taken to be true, to serve as a premise for further reasoning
7)
[SOURCE: ISO/IEC/PRF 21838-1:— , 3.9, modified — Note to entry removed.]
3.3
business viewpoint
viewpoint (3.28) that is concerned with the purpose, scope and policies governing the activities of the
specified ecosystem (3.10)
3.4
class
type
general entity (3.11)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.2, modified — “type” added as second preferred term, note to
entry removed.]
3.5
collection
group of particulars (3.19)
8)
[SOURCE: ISO/IEC/PRF 21838-2:— , 3.4, modified — Notes to entry removed.]
3.6
concept
unit of knowledge created by a unique combination of characteristics
Note 1 to entry: Concepts are not necessarily bound to particular natural languages. They are, however,
influenced by the social or cultural background which often leads to different categorizations.
Note 2 to entry: As a knowledge component, a concept can be specialized and generalized as components can.
[SOURCE: ISO 1087:2019, 3.2.7, modified — Note 2 to entry replaced.]
3.7
definition
representation of a concept by a descriptive statement which serves to differentiate it from related
concepts
[SOURCE: ISO 1087:2019, 3.3.1]
3.8
domain
collection (3.5) of entities (3.11) of interest to a certain community or discipline
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.17, modified — Example and note to entry removed.]
7) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-1:2021.
8) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-2.2:2021.
2 © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

3.9
domain ontology
ontology (3.18) whose terms (3.26) represent classes or types (3.4) and, optionally, certain particulars
(3.19) (called ‘distinguished individuals’) in some domain (3.8)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.18]
3.10
ecosystem
structured systems (3.25) and communities that are governed by general rules
3.11
entity
object
item that is perceivable or conceivable
Note 1 to entry: The terms ‘entity’ and ‘object’ are catch-all terms analogous to ‘something’. In terminology
circles ‘object’ is commonly used in this way. In ontology circles, ‘entity’ and ‘thing’ are commonly used.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.1]
3.12
expression
word or group of words or corresponding symbols that can be used in making an assertion
Note 1 to entry: Expressions are divided into natural language expressions and expressions in a formal language.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.5]
3.13
formal language
language that is machine readable and has well-defined semantics
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.10, modified — Note removed.]
3.14
formal theory
collection (3.5) of definitions (3.7) and axioms (3.2) expressed in a formal language (3.13)
[SOURCE: ISO/IEC/PRF 21838-1: —, 3.11, modified — Note removed.]
3.15
instance
particular (3.19) that instantiates some universal (3.27)
[SOURCE: ISO/IEC/PRF 21838-2:—, 3.6, modified — Example removed.]
3.16
interoperability
ability of a system (3.25) or a product to work with other systems (3.25) or products without special
effort on the part of the customer
Note 1 to entry: Under traditional ICT focus, interoperability is ability of two or more systems or components to
[29]
exchange information and to use the information that has been exchanged .
[SOURCE: IEEE Standards Glossary]
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ISO 23903:2021(E)

3.17
model
unambiguous, abstract conception of some parts or aspects of the real world corresponding to the
modelling goals
Note 1 to entry: The relevant stakeholders define the provided view
...

INTERNATIONAL ISO
STANDARD 23903
First edition
2021-04
Corrected version
2021-07
Health informatics — Interoperability
and integration reference architecture
— Model and framework
Informatique de santé — Architecture de référence d'interopérabilité
et d'intégration — Modèle et cadre
Reference number
ISO 23903:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23903:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 23903:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 5
5 Overview on standard system architecture. 5
6 Interoperability and Integration Reference Architecture for ICT Supported Systems .6
6.1 Interoperability and Integration Reference Architecture domains and granularity levels . 6
6.2 Interoperability and Integration Reference Architecture model for ICT supported
systems . 7
6.3 Interoperability and Integration Reference Architecture framework . 8
6.3.1 Basic requirements . 8
6.3.2 Management of relationships in the Interoperability and Integration
Reference Architecture . 9
6.3.3 Business process modelling using the Interoperability and Integration
Reference Architecture . 9
Annex A (informative) Cross-domain interoperability for security and privacy aware EHR
communication .11
Annex B (informative) Interoperability between different communication standards .13
Annex C (informative) Integration of standards in ISO 12967 (all parts) .15
Annex D (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach in ISO 13972.18
Annex E (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach for the representation and harmonization of alternative
reference architectures .19
Bibliography .21
© ISO 2021 – All rights reserved iii

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ISO 23903:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 251, Health
informatics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
This corrected version of ISO 23903:2021 incorporates the following corrections:
— Figure E.1 has been corrected.
iv © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

Introduction
0.1  Preface
This document supports the integration of a) specifications from different domains with their specific
methodologies, terminologies and ontologies including specific specification style as well as b) systems
based on those specifications. Enabling the use-case-specific identification and consistent, formal
representation including constraints of necessary components with their specific concepts and their
relationships, this document facilitates the deployment of existing standards and systems, the analysis
and improvement of specifications under revision as well as the design of new projects.
This document provides an overview of the Interoperability and Integration Reference Architecture
[1][2]
(first introduced in the 1990s as the Generic Component Model – GCM ), providing scope, justification
and explanation of key concepts and the resulting model and framework. It contains explanatory
material on how this Interoperability and Integration Reference Architecture is interpreted and applied
by its users, who might include standards writers and architects of interoperable systems, but also
systems integrators.
The ongoing organizational, methodological and technological paradigm changes in health and
social care result in health systems transformation toward P5 (personalized, preventive, predictive,
participative precision) systems medicine as fully distributed, highly dynamic, strongly integrated,
multi-disciplinary (or multi-domain) intelligent ecosystems, comprising both structured systems,
[3]
communities governed by rules, and combinations thereof .
0.2  Interoperability levels
Interoperability (see 3.16) has evolved during the last 30 years from structured messaging (e.g. EDI,
1) 2) [4]
HL7® messaging) over sharing concepts [e.g. openEHR® Archetypes, ISO 13940 (system of
concepts to support continuity of care)] – both representing the data/information exchange paradigm
– to cooperation at application level (e.g. Web services). All those solutions focus on information and
communication technologies (ICT) systems interoperability using ICT terminologies and ontologies
for representing data, information, or even concepts and knowledge, thereby distinguishing the three
interoperability levels: a) foundational, b) structural, and c) semantic interoperability.
On the move towards digital health, ICT systems get more closely integrated in the real world business
process. This move requires supporting advanced, knowledge-level and business process focused
interoperability between all principals acting in those ecosystems such as persons, organizations,
devices, applications, components, or objects to achieve the common business objectives. As knowledge,
methodologies and terminologies of the domains involved in the business case and represented through
those domains’ ontologies, but also individual contexts, abilities and capabilities are highly different,
they must be shared and adapted in advance or dynamically at runtime, enabling adequate cooperation
[5]
of actors and systems involved. Table 1 summarizes the different interoperability levels .
1) HL7 is a registered trademark of Health Level Seven International. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
2) openEHR is a registered trademark of the openEHR Foundation. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO 23903:2021(E)

Table 1 — Interoperability levels
Information Perspective Organization Perspective
Interoperability
Instances Interoperability Level
Level
Technical Technical plug&play, signal & protocol com- Light-weight interactions
patibility
Structural Simple EDI, envelopes Data sharing
Syntactic Messages and clinical documents with agreed Information sharing
vocabulary
Semantic Advanced messaging with common information Knowledge sharing at IT concept level in
models and terminologies computer-parsable form
Coordination
O rg a n iza t i o n / Common business process Knowledge sharing at business concept level
Service
Agreed service function level cooperation
Knowledge based Multi-domain processes Knowledge sharing at domain level
Cross-domain cooperation
Skills based Individual engagement in multiple domains Knowledge sharing in individual context
Moderated end-user collaboration
0.3  Motivation for the Interoperability and Integration Reference Architecture
Meeting the objectives of improving safety, quality and efficiency of care with ICT support requires
advancing interoperability between computer systems towards a business-process-specific co-
operation of actors representing the different domains participating in the business case. For that
purpose, the agreed domain knowledge, but also the individual and shared context (language, education,
skills, experiences, psychological, social, occupational, environmental aspects, etc.), need to be
represented correctly and formally for integration with the ICT system as part of the business system.
As the domain experts involved describe specific aspects of that business system in their own specific
contexts and using specific terminologies and ontologies, methodologies and frameworks, the resulting
informational representations are often quite inconsistent, requiring a peer-to-peer interoperability
adaptation process. Adapting existing standardized informational representations of domain-specific
use cases to changing contexts or contexts including multiple domains requires another common
harmonized informational representation, resulting in permanent revisions of specifications.
Modelling systems for multi-domain interoperability requires the advancement from the data model,
information model, and ICT domain knowledge perspective to the knowledge perspective of the
[6]
business domains . For achieving the latter, the relevant stakeholders are responsible to define the
provided view of the model as well as the way of structuring and naming the concepts of the problem
space. First capturing key concepts and key relations at a high level of abstraction, different abstraction
levels can be used iteratively. Thereby, the first iteration is performed in a top-down manner to
guarantee the conceptual integrity of the model. This demands meeting design principles such as
[7] [8]
orthogonality, generality, parsimony, and propriety. ISO 30401 defines the requirements for
knowledge management systems in organizations to meet business objectives.
It is impossible to represent the highly complex, highly dynamic, multi-disciplinary/multi-domain
healthcare system by one domain‘s terminology/ontology or – even worse for the reasons mentioned
right before - by exclusively using ICT ontologies and ICT specific representation styles.
The alternative is an abstract, domain-independent representation of systems using Universal Type
[9]
Theory and corresponding logics. The mathematical concept representation using a Meta Reference
[9]
Architecture according to the formal theory of the Barendregt Cube with Parameters in combination
with systems engineering methodologies allows representing any system architecturally (i.e. the
system’s components, their functions and internal as well as external relations) by generically describing
its composition/decomposition and behaviour from the perspectives of all domains of relevance in a
specific business case. A third dimension describes the system’s development process such as evolution
vi © ISO 2021 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 23903:2021(E)

for living systems, manufacturing for technical systems, or a software development process, resulting
in a generic system model or Generic Reference Architecture presented in Figure 1. Details regarding
the dimensions of the model are explained in Clause 5 and Clause 6.
Figure 1 — Generic Reference Architecture model
To represent advanced interoperability and integration settings, different domain-specific
representations are linked to the same real world component. Therefore, an abstract and generic
reference architecture is needed which is able to represent any aspect or domain of interest. For
correctly and formally representing the concepts and relations of the domain-specific subsystems
involved in that business case, those subsystems are represented by their corresponding approved
domain ontologies, resulting in a system-theoretical, architecture-centric, top-level ontology driven
[10][11]
approach . Requirements for top level ontologies are specified in ISO 21838 (all parts). Health
3)
domain ontologies are SNOMED-CT® or specific ontologies such as the Open Biomedical Ontologies
[12] [13]
(OBO), including the Gene Ontology, maintained by the OBO Foundry .
As we can consistently model and compute only systems of reasonable complexity, the Generic Reference
Architecture model (Figure 1) can be used recursively at different granularity levels, so representing,
e.g. the continuum of real-world systems from elementary particles to the universe. The concepts of
the system’s components and their relations are represented in appropriate expressions in natural or
formal languages up to the basic level of primitives. The system analysis or design needs to address
partial systems when considering higher granularity levels of the system in question.
0.4  Technical approach
A system is a composition of interrelated components, ordered to accomplish a specific function or a
set of functions. Systems can be decomposed into subsystems or composed to form super-systems.
There are constructive or structural and behavioural or functional aspects of systems. According to
[14]
IEEE 1471, the architecture of a system is the fundamental organization of that system embodied in
its components, their relationships to each other and to the environment, and the principles guiding its
design and evolution. Rules for selecting and constraining components and functions as well as relations
according to a business case are called policies. Policies define the intended behaviour of a system. For
living systems, factors such as homeostasis, with the attributes of self-organization and self-regulation
as well as growth and development, reproduction, with the associated heredity (structure preservation)
and mutation (structural change), and higher development through selection of best-adapted variants
out of a large number make the description of living systems more complicated than that of technical
[15]
systems .
3) SNOMED CT is the registered trademark of the International Health Terminology Standards Development
Organisation (IHTSDO). This information is given for the convenience of users of this document and does not
constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved vii

---------------------- Page: 7 ----------------------
ISO 23903:2021(E)

In the 1970s and 1980s, a data level interoperability approach was developed by defining the
application and technology agnostic standard data exchange format EDI (electronic data interchange)
in order to transform proprietary data formats into the standard data format and vice versa.
[16]
Thus International Standards arose such as ISO 9735 (EDIFACT), or its healthcare-specific
[17]
pendant ISO/HL7 27931:2009, an application protocol for electronic data exchange in healthcare
environments. This document defines a generic system architecture for knowledge level interoperability.
It allows consistently transforming and interrelating any domain specific subsystem’s structure and
behaviour (e.g. domain specific standards and specifications) by ontologically representing its concepts
and relationships at the real world system component’s level of granularity in the abstract generic
component system. In other words, the domain specific subsystem (e.g. a domain specific standard or
specification) is re-engineered using the Interoperability and Integration Reference Architecture, by
that way providing a standardized interface to that specification. In this way, the methodology offered
in this document maps between domain specific or proprietary systems and their representation as
specification or domain specific standard by transforming them into a standard system architecture
and vice versa. Annex A demonstrates the integration of two domain specific standards by reengineering
[18]
the ISO 13606-1 Reference Model and the HL7® Composite Security and Privacy Domain Analysis
[19]
Model and combining them in an Interoperability and Integration Reference Architecture model
instance. Annex B demonstrates the integration of different communication standards by reengineering
4) 4)
HL7 v3® methodology and creating an adequate HL7 v2® methodology and transforming them into
an Interoperability and Integration Reference Architecture instance. In this way, the Interoperability
and Integration Reference Architecture supports the mutual transformation of those communications
standards for the sake of interoperability of existing solutions. For ontologically representing the
[20]
models, the Communication Standards Ontology (CSO) has been used. Figure 2 correspondingly
presents this standard’s interoperability approach. Annex C demonstrates the integration of different
[21]
standards in the light of ISO 12967(all parts) , while Annex D presents the approach in context of
[22]
ISO 13972 . Finally, Annex E demonstrates the deployment of this document’s Interoperability and
Integration Reference Architecture for the representation and harmonization of alternative reference
architectures.
4) HL7 v3 and HL7 v2 are registered trademarks of Health Level Seven International. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of the products named.
viii © ISO 2021 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 23903:2021(E)

Figure 2 — Overview of this document’s interoperability approach
Bound to the GCM Framework, inter-domain relationships need to happen at the same level of
[23]
granularity . To get there, intra-domain specializations/generalizations are performed.
© ISO 2021 – All rights reserved ix

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INTERNATIONAL STANDARD ISO 23903:2021(E)
Health informatics — Interoperability and integration
reference architecture — Model and framework
1 Scope
This document enables the advancement of interoperability from the data/information exchange
paradigm to knowledge sharing at decreasing level of abstraction, starting at IT concept level (semantic
coordination) through business domain concept level (agreed service function level cooperation),
domain level (cross-domain cooperation) up to individual context (skills-based end-user collaboration).
The document defines a model and framework for a harmonized representation of existing or intended
systems with a specific focus on ICT-supported business systems. The Interoperability and Integration
Reference Architecture supports ontology harmonization or knowledge harmonization to enable
interoperability between, and integration of, systems, standards and solutions at any level of complexity
without the demand for continuously adapting/revising those specifications. The approach can be
used for analysing, designing, integrating, and running any type of systems. For realizing advanced
interoperability, flexible, scalable, business-controlled, adaptive, knowledge-based, intelligent health
and social ecosystems need to follow a systems-oriented, architecture-centric, ontology-based and
policy-driven approach.
The languages for representing the different views on systems such as ontology languages like
[24] [25] [26]
Common Logic (CL) (ISO/IEC 24707 ) and Web Ontology Language (OWL) – specifically OWL 2
5)
(World Wide Web Consortium (W3C® ), languages for modeling and integrating business processes
6)
like Business Process Modeling Language (BPML) (OMG® ), but also OMG’s Unified Modeling
[27]
Language (UML, also specified as ISO/IEC 19505 ) based representation styles for the different
ISO/IEC 10746 (all parts) views are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10746 (all parts), Information technology — Open distributed processing — Reference model
ISO 22600 (all parts), Health informatics — Privilege management and access control
ISO/IEC 21838 (all parts), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
5) W3C is a registered trademark of the World Wide Web Consortium. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
6) OMG is a registered trademark of The Object Management Group®. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
© ISO 2021 – All rights reserved 1

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ISO 23903:2021(E)

3.1
architecture
set of rules to define the structure of a system (3.25) and the interrelationships between its parts
[SOURCE: ISO/IEC 10746-2:2009, 6.6, modified — "(of a system)" removed from term.]
3.2
axiom
statement that is taken to be true, to serve as a premise for further reasoning
7)
[SOURCE: ISO/IEC/PRF 21838-1:— , 3.9, modified — Note to entry removed.]
3.3
business viewpoint
viewpoint (3.28) that is concerned with the purpose, scope and policies governing the activities of the
specified ecosystem (3.10)
3.4
class
type
general entity (3.11)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.2, modified — “type” added as second preferred term, note to
entry removed.]
3.5
collection
group of particulars (3.19)
8)
[SOURCE: ISO/IEC/PRF 21838-2:— , 3.4, modified — Notes to entry removed.]
3.6
concept
unit of knowledge created by a unique combination of characteristics
Note 1 to entry: Concepts are not necessarily bound to particular natural languages. They are, however,
influenced by the social or cultural background which often leads to different categorizations.
Note 2 to entry: As a knowledge component, a concept can be specialized and generalized as components can.
[SOURCE: ISO 1087:2019, 3.2.7, modified — Note 2 to entry replaced.]
3.7
definition
representation of a concept by a descriptive statement which serves to differentiate it from related
concepts
[SOURCE: ISO 1087:2019, 3.3.1]
3.8
domain
collection (3.5) of entities (3.11) of interest to a certain community or discipline
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.17, modified — Example and note to entry removed.]
7) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-1:2021.
8) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-2.2:2021.
2 © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

3.9
domain ontology
ontology (3.18) whose terms (3.26) represent classes or types (3.4) and, optionally, certain particulars
(3.19) (called ‘distinguished individuals’) in some domain (3.8)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.18]
3.10
ecosystem
structured systems (3.25) and communities that are governed by general rules
3.11
entity
object
item that is perceivable or conceivable
Note 1 to entry: The terms ‘entity’ and ‘object’ are catch-all terms analogous to ‘something’. In terminology
circles ‘object’ is commonly used in this way. In ontology circles, ‘entity’ and ‘thing’ are commonly used.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.1]
3.12
expression
word or group of words or corresponding symbols that can be used in making an assertion
Note 1 to entry: Expressions are divided into natural language expressions and expressions in a formal language.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.5]
3.13
formal language
language that is machine readable and has well-defined semantics
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.10, modified — Note removed.]
3.14
formal theory
collection (3.5) of definitions (3.7) and axioms (3.2) expressed in a formal language (3.13)
[SOURCE: ISO/IEC/PRF 21838-1: —, 3.11, modified — Note removed.]
3.15
instance
particular (3.19) that instantiates some universal (3.27)
[SOURCE: ISO/IEC/PRF 21838-2:—, 3.6, modified — Example removed.]
3.16
interoperability
ability of a system (3.25) or a product to work with other systems (3.25) or products without special
effort on the part of the customer
Note 1 to entry: Under traditional ICT focus, interoperability is ability of two or more systems or components to
[29]
exchange information and to use the information that has been exchanged .
[SOURCE: IEEE Standards Glossary]
© ISO 2021 – All rights reserved 3

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ISO 23903:2021(E)

3.17
model
unambiguous, abstract conception of som
...

INTERNATIONAL ISO
STANDARD 23903
First edition
2021-04
Corrected version
2021-07
Health informatics — Interoperability
and integration reference architecture
— Model and framework
Informatique de santé — Architecture de référence d'interopérabilité
et d'intégration — Modèle et cadre
Reference number
ISO 23903:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23903:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 23903:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 5
5 Overview on standard system architecture. 5
6 Interoperability and Integration Reference Architecture for ICT Supported Systems .6
6.1 Interoperability and Integration Reference Architecture domains and granularity levels . 6
6.2 Interoperability and Integration Reference Architecture model for ICT supported
systems . 7
6.3 Interoperability and Integration Reference Architecture framework . 8
6.3.1 Basic requirements . 8
6.3.2 Management of relationships in the Interoperability and Integration
Reference Architecture . 9
6.3.3 Business process modelling using the Interoperability and Integration
Reference Architecture . 9
Annex A (informative) Cross-domain interoperability for security and privacy aware EHR
communication .11
Annex B (informative) Interoperability between different communication standards .13
Annex C (informative) Integration of standards in ISO 12967 (all parts) .15
Annex D (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach in ISO 13972.18
Annex E (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach for the representation and harmonization of alternative
reference architectures .19
Bibliography .21
© ISO 2021 – All rights reserved iii

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ISO 23903:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 251, Health
informatics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
This corrected version of ISO 23903:2021 incorporates the following corrections:
— Figure E.1 has been corrected.
iv © ISO 2021 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 23903:2021(E)

Introduction
0.1  Preface
This document supports the integration of a) specifications from different domains with their specific
methodologies, terminologies and ontologies including specific specification style as well as b) systems
based on those specifications. Enabling the use-case-specific identification and consistent, formal
representation including constraints of necessary components with their specific concepts and their
relationships, this document facilitates the deployment of existing standards and systems, the analysis
and improvement of specifications under revision as well as the design of new projects.
This document provides an overview of the Interoperability and Integration Reference Architecture
[1][2]
(first introduced in the 1990s as the Generic Component Model – GCM ), providing scope, justification
and explanation of key concepts and the resulting model and framework. It contains explanatory
material on how this Interoperability and Integration Reference Architecture is interpreted and applied
by its users, who might include standards writers and architects of interoperable systems, but also
systems integrators.
The ongoing organizational, methodological and technological paradigm changes in health and
social care result in health systems transformation toward P5 (personalized, preventive, predictive,
participative precision) systems medicine as fully distributed, highly dynamic, strongly integrated,
multi-disciplinary (or multi-domain) intelligent ecosystems, comprising both structured systems,
[3]
communities governed by rules, and combinations thereof .
0.2  Interoperability levels
Interoperability (see 3.16) has evolved during the last 30 years from structured messaging (e.g. EDI,
1) 2) [4]
HL7® messaging) over sharing concepts [e.g. openEHR® Archetypes, ISO 13940 (system of
concepts to support continuity of care)] – both representing the data/information exchange paradigm
– to cooperation at application level (e.g. Web services). All those solutions focus on information and
communication technologies (ICT) systems interoperability using ICT terminologies and ontologies
for representing data, information, or even concepts and knowledge, thereby distinguishing the three
interoperability levels: a) foundational, b) structural, and c) semantic interoperability.
On the move towards digital health, ICT systems get more closely integrated in the real world business
process. This move requires supporting advanced, knowledge-level and business process focused
interoperability between all principals acting in those ecosystems such as persons, organizations,
devices, applications, components, or objects to achieve the common business objectives. As knowledge,
methodologies and terminologies of the domains involved in the business case and represented through
those domains’ ontologies, but also individual contexts, abilities and capabilities are highly different,
they must be shared and adapted in advance or dynamically at runtime, enabling adequate cooperation
[5]
of actors and systems involved. Table 1 summarizes the different interoperability levels .
1) HL7 is a registered trademark of Health Level Seven International. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
2) openEHR is a registered trademark of the openEHR Foundation. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO 23903:2021(E)

Table 1 — Interoperability levels
Information Perspective Organization Perspective
Interoperability
Instances Interoperability Level
Level
Technical Technical plug&play, signal & protocol com- Light-weight interactions
patibility
Structural Simple EDI, envelopes Data sharing
Syntactic Messages and clinical documents with agreed Information sharing
vocabulary
Semantic Advanced messaging with common information Knowledge sharing at IT concept level in
models and terminologies computer-parsable form
Coordination
O rg a n iza t i o n / Common business process Knowledge sharing at business concept level
Service
Agreed service function level cooperation
Knowledge based Multi-domain processes Knowledge sharing at domain level
Cross-domain cooperation
Skills based Individual engagement in multiple domains Knowledge sharing in individual context
Moderated end-user collaboration
0.3  Motivation for the Interoperability and Integration Reference Architecture
Meeting the objectives of improving safety, quality and efficiency of care with ICT support requires
advancing interoperability between computer systems towards a business-process-specific co-
operation of actors representing the different domains participating in the business case. For that
purpose, the agreed domain knowledge, but also the individual and shared context (language, education,
skills, experiences, psychological, social, occupational, environmental aspects, etc.), need to be
represented correctly and formally for integration with the ICT system as part of the business system.
As the domain experts involved describe specific aspects of that business system in their own specific
contexts and using specific terminologies and ontologies, methodologies and frameworks, the resulting
informational representations are often quite inconsistent, requiring a peer-to-peer interoperability
adaptation process. Adapting existing standardized informational representations of domain-specific
use cases to changing contexts or contexts including multiple domains requires another common
harmonized informational representation, resulting in permanent revisions of specifications.
Modelling systems for multi-domain interoperability requires the advancement from the data model,
information model, and ICT domain knowledge perspective to the knowledge perspective of the
[6]
business domains . For achieving the latter, the relevant stakeholders are responsible to define the
provided view of the model as well as the way of structuring and naming the concepts of the problem
space. First capturing key concepts and key relations at a high level of abstraction, different abstraction
levels can be used iteratively. Thereby, the first iteration is performed in a top-down manner to
guarantee the conceptual integrity of the model. This demands meeting design principles such as
[7] [8]
orthogonality, generality, parsimony, and propriety. ISO 30401 defines the requirements for
knowledge management systems in organizations to meet business objectives.
It is impossible to represent the highly complex, highly dynamic, multi-disciplinary/multi-domain
healthcare system by one domain‘s terminology/ontology or – even worse for the reasons mentioned
right before - by exclusively using ICT ontologies and ICT specific representation styles.
The alternative is an abstract, domain-independent representation of systems using Universal Type
[9]
Theory and corresponding logics. The mathematical concept representation using a Meta Reference
[9]
Architecture according to the formal theory of the Barendregt Cube with Parameters in combination
with systems engineering methodologies allows representing any system architecturally (i.e. the
system’s components, their functions and internal as well as external relations) by generically describing
its composition/decomposition and behaviour from the perspectives of all domains of relevance in a
specific business case. A third dimension describes the system’s development process such as evolution
vi © ISO 2021 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 23903:2021(E)

for living systems, manufacturing for technical systems, or a software development process, resulting
in a generic system model or Generic Reference Architecture presented in Figure 1. Details regarding
the dimensions of the model are explained in Clause 5 and Clause 6.
Figure 1 — Generic Reference Architecture model
To represent advanced interoperability and integration settings, different domain-specific
representations are linked to the same real world component. Therefore, an abstract and generic
reference architecture is needed which is able to represent any aspect or domain of interest. For
correctly and formally representing the concepts and relations of the domain-specific subsystems
involved in that business case, those subsystems are represented by their corresponding approved
domain ontologies, resulting in a system-theoretical, architecture-centric, top-level ontology driven
[10][11]
approach . Requirements for top level ontologies are specified in ISO 21838 (all parts). Health
3)
domain ontologies are SNOMED-CT® or specific ontologies such as the Open Biomedical Ontologies
[12] [13]
(OBO), including the Gene Ontology, maintained by the OBO Foundry .
As we can consistently model and compute only systems of reasonable complexity, the Generic Reference
Architecture model (Figure 1) can be used recursively at different granularity levels, so representing,
e.g. the continuum of real-world systems from elementary particles to the universe. The concepts of
the system’s components and their relations are represented in appropriate expressions in natural or
formal languages up to the basic level of primitives. The system analysis or design needs to address
partial systems when considering higher granularity levels of the system in question.
0.4  Technical approach
A system is a composition of interrelated components, ordered to accomplish a specific function or a
set of functions. Systems can be decomposed into subsystems or composed to form super-systems.
There are constructive or structural and behavioural or functional aspects of systems. According to
[14]
IEEE 1471, the architecture of a system is the fundamental organization of that system embodied in
its components, their relationships to each other and to the environment, and the principles guiding its
design and evolution. Rules for selecting and constraining components and functions as well as relations
according to a business case are called policies. Policies define the intended behaviour of a system. For
living systems, factors such as homeostasis, with the attributes of self-organization and self-regulation
as well as growth and development, reproduction, with the associated heredity (structure preservation)
and mutation (structural change), and higher development through selection of best-adapted variants
out of a large number make the description of living systems more complicated than that of technical
[15]
systems .
3) SNOMED CT is the registered trademark of the International Health Terminology Standards Development
Organisation (IHTSDO). This information is given for the convenience of users of this document and does not
constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved vii

---------------------- Page: 7 ----------------------
ISO 23903:2021(E)

In the 1970s and 1980s, a data level interoperability approach was developed by defining the
application and technology agnostic standard data exchange format EDI (electronic data interchange)
in order to transform proprietary data formats into the standard data format and vice versa.
[16]
Thus International Standards arose such as ISO 9735 (EDIFACT), or its healthcare-specific
[17]
pendant ISO/HL7 27931:2009, an application protocol for electronic data exchange in healthcare
environments. This document defines a generic system architecture for knowledge level interoperability.
It allows consistently transforming and interrelating any domain specific subsystem’s structure and
behaviour (e.g. domain specific standards and specifications) by ontologically representing its concepts
and relationships at the real world system component’s level of granularity in the abstract generic
component system. In other words, the domain specific subsystem (e.g. a domain specific standard or
specification) is re-engineered using the Interoperability and Integration Reference Architecture, by
that way providing a standardized interface to that specification. In this way, the methodology offered
in this document maps between domain specific or proprietary systems and their representation as
specification or domain specific standard by transforming them into a standard system architecture
and vice versa. Annex A demonstrates the integration of two domain specific standards by reengineering
[18]
the ISO 13606-1 Reference Model and the HL7® Composite Security and Privacy Domain Analysis
[19]
Model and combining them in an Interoperability and Integration Reference Architecture model
instance. Annex B demonstrates the integration of different communication standards by reengineering
4) 4)
HL7 v3® methodology and creating an adequate HL7 v2® methodology and transforming them into
an Interoperability and Integration Reference Architecture instance. In this way, the Interoperability
and Integration Reference Architecture supports the mutual transformation of those communications
standards for the sake of interoperability of existing solutions. For ontologically representing the
[20]
models, the Communication Standards Ontology (CSO) has been used. Figure 2 correspondingly
presents this standard’s interoperability approach. Annex C demonstrates the integration of different
[21]
standards in the light of ISO 12967(all parts) , while Annex D presents the approach in context of
[22]
ISO 13972 . Finally, Annex E demonstrates the deployment of this document’s Interoperability and
Integration Reference Architecture for the representation and harmonization of alternative reference
architectures.
4) HL7 v3 and HL7 v2 are registered trademarks of Health Level Seven International. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of the products named.
viii © ISO 2021 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 23903:2021(E)

Figure 2 — Overview of this document’s interoperability approach
Bound to the GCM Framework, inter-domain relationships need to happen at the same level of
[23]
granularity . To get there, intra-domain specializations/generalizations are performed.
© ISO 2021 – All rights reserved ix

---------------------- Page: 9 ----------------------
INTERNATIONAL STANDARD ISO 23903:2021(E)
Health informatics — Interoperability and integration
reference architecture — Model and framework
1 Scope
This document enables the advancement of interoperability from the data/information exchange
paradigm to knowledge sharing at decreasing level of abstraction, starting at IT concept level (semantic
coordination) through business domain concept level (agreed service function level cooperation),
domain level (cross-domain cooperation) up to individual context (skills-based end-user collaboration).
The document defines a model and framework for a harmonized representation of existing or intended
systems with a specific focus on ICT-supported business systems. The Interoperability and Integration
Reference Architecture supports ontology harmonization or knowledge harmonization to enable
interoperability between, and integration of, systems, standards and solutions at any level of complexity
without the demand for continuously adapting/revising those specifications. The approach can be
used for analysing, designing, integrating, and running any type of systems. For realizing advanced
interoperability, flexible, scalable, business-controlled, adaptive, knowledge-based, intelligent health
and social ecosystems need to follow a systems-oriented, architecture-centric, ontology-based and
policy-driven approach.
The languages for representing the different views on systems such as ontology languages like
[24] [25] [26]
Common Logic (CL) (ISO/IEC 24707 ) and Web Ontology Language (OWL) – specifically OWL 2
5)
(World Wide Web Consortium (W3C® ), languages for modeling and integrating business processes
6)
like Business Process Modeling Language (BPML) (OMG® ), but also OMG’s Unified Modeling
[27]
Language (UML, also specified as ISO/IEC 19505 ) based representation styles for the different
ISO/IEC 10746 (all parts) views are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10746 (all parts), Information technology — Open distributed processing — Reference model
ISO 22600 (all parts), Health informatics — Privilege management and access control
ISO/IEC 21838 (all parts), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
5) W3C is a registered trademark of the World Wide Web Consortium. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
6) OMG is a registered trademark of The Object Management Group®. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
© ISO 2021 – All rights reserved 1

---------------------- Page: 10 ----------------------
ISO 23903:2021(E)

3.1
architecture
set of rules to define the structure of a system (3.25) and the interrelationships between its parts
[SOURCE: ISO/IEC 10746-2:2009, 6.6, modified — "(of a system)" removed from term.]
3.2
axiom
statement that is taken to be true, to serve as a premise for further reasoning
7)
[SOURCE: ISO/IEC/PRF 21838-1:— , 3.9, modified — Note to entry removed.]
3.3
business viewpoint
viewpoint (3.28) that is concerned with the purpose, scope and policies governing the activities of the
specified ecosystem (3.10)
3.4
class
type
general entity (3.11)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.2, modified — “type” added as second preferred term, note to
entry removed.]
3.5
collection
group of particulars (3.19)
8)
[SOURCE: ISO/IEC/PRF 21838-2:— , 3.4, modified — Notes to entry removed.]
3.6
concept
unit of knowledge created by a unique combination of characteristics
Note 1 to entry: Concepts are not necessarily bound to particular natural languages. They are, however,
influenced by the social or cultural background which often leads to different categorizations.
Note 2 to entry: As a knowledge component, a concept can be specialized and generalized as components can.
[SOURCE: ISO 1087:2019, 3.2.7, modified — Note 2 to entry replaced.]
3.7
definition
representation of a concept by a descriptive statement which serves to differentiate it from related
concepts
[SOURCE: ISO 1087:2019, 3.3.1]
3.8
domain
collection (3.5) of entities (3.11) of interest to a certain community or discipline
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.17, modified — Example and note to entry removed.]
7) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-1:2021.
8) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-2.2:2021.
2 © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

3.9
domain ontology
ontology (3.18) whose terms (3.26) represent classes or types (3.4) and, optionally, certain particulars
(3.19) (called ‘distinguished individuals’) in some domain (3.8)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.18]
3.10
ecosystem
structured systems (3.25) and communities that are governed by general rules
3.11
entity
object
item that is perceivable or conceivable
Note 1 to entry: The terms ‘entity’ and ‘object’ are catch-all terms analogous to ‘something’. In terminology
circles ‘object’ is commonly used in this way. In ontology circles, ‘entity’ and ‘thing’ are commonly used.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.1]
3.12
expression
word or group of words or corresponding symbols that can be used in making an assertion
Note 1 to entry: Expressions are divided into natural language expressions and expressions in a formal language.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.5]
3.13
formal language
language that is machine readable and has well-defined semantics
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.10, modified — Note removed.]
3.14
formal theory
collection (3.5) of definitions (3.7) and axioms (3.2) expressed in a formal language (3.13)
[SOURCE: ISO/IEC/PRF 21838-1: —, 3.11, modified — Note removed.]
3.15
instance
particular (3.19) that instantiates some universal (3.27)
[SOURCE: ISO/IEC/PRF 21838-2:—, 3.6, modified — Example removed.]
3.16
interoperability
ability of a system (3.25) or a product to work with other systems (3.25) or products without special
effort on the part of the customer
Note 1 to entry: Under traditional ICT focus, interoperability is ability of two or more systems or components to
[29]
exchange information and to use the information that has been exchanged .
[SOURCE: IEEE Standards Glossary]
© ISO 2021 – All rights reserved 3

---------------------- Page: 12 ----------------------
ISO 23903:2021(E)

3.17
model
unambiguous, abstract conception of som
...

INTERNATIONAL ISO
STANDARD 23903
First edition
2021-04
Corrected version
2021-07
Health informatics — Interoperability
and integration reference architecture
— Model and framework
Informatique de santé — Architecture de référence d'interopérabilité
et d'intégration — Modèle et cadre
Reference number
ISO 23903:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23903:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 23903:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 5
5 Overview on standard system architecture. 5
6 Interoperability and Integration Reference Architecture for ICT Supported Systems .6
6.1 Interoperability and Integration Reference Architecture domains and granularity levels . 6
6.2 Interoperability and Integration Reference Architecture model for ICT supported
systems . 7
6.3 Interoperability and Integration Reference Architecture framework . 8
6.3.1 Basic requirements . 8
6.3.2 Management of relationships in the Interoperability and Integration
Reference Architecture . 9
6.3.3 Business process modelling using the Interoperability and Integration
Reference Architecture . 9
Annex A (informative) Cross-domain interoperability for security and privacy aware EHR
communication .11
Annex B (informative) Interoperability between different communication standards .13
Annex C (informative) Integration of standards in ISO 12967 (all parts) .15
Annex D (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach in ISO 13972.18
Annex E (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach for the representation and harmonization of alternative
reference architectures .19
Bibliography .21
© ISO 2021 – All rights reserved iii

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ISO 23903:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 251, Health
informatics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
This corrected version of ISO 23903:2021 incorporates the following corrections:
— Figure E.1 has been corrected.
iv © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

Introduction
0.1  Preface
This document supports the integration of a) specifications from different domains with their specific
methodologies, terminologies and ontologies including specific specification style as well as b) systems
based on those specifications. Enabling the use-case-specific identification and consistent, formal
representation including constraints of necessary components with their specific concepts and their
relationships, this document facilitates the deployment of existing standards and systems, the analysis
and improvement of specifications under revision as well as the design of new projects.
This document provides an overview of the Interoperability and Integration Reference Architecture
[1][2]
(first introduced in the 1990s as the Generic Component Model – GCM ), providing scope, justification
and explanation of key concepts and the resulting model and framework. It contains explanatory
material on how this Interoperability and Integration Reference Architecture is interpreted and applied
by its users, who might include standards writers and architects of interoperable systems, but also
systems integrators.
The ongoing organizational, methodological and technological paradigm changes in health and
social care result in health systems transformation toward P5 (personalized, preventive, predictive,
participative precision) systems medicine as fully distributed, highly dynamic, strongly integrated,
multi-disciplinary (or multi-domain) intelligent ecosystems, comprising both structured systems,
[3]
communities governed by rules, and combinations thereof .
0.2  Interoperability levels
Interoperability (see 3.16) has evolved during the last 30 years from structured messaging (e.g. EDI,
1) 2) [4]
HL7® messaging) over sharing concepts [e.g. openEHR® Archetypes, ISO 13940 (system of
concepts to support continuity of care)] – both representing the data/information exchange paradigm
– to cooperation at application level (e.g. Web services). All those solutions focus on information and
communication technologies (ICT) systems interoperability using ICT terminologies and ontologies
for representing data, information, or even concepts and knowledge, thereby distinguishing the three
interoperability levels: a) foundational, b) structural, and c) semantic interoperability.
On the move towards digital health, ICT systems get more closely integrated in the real world business
process. This move requires supporting advanced, knowledge-level and business process focused
interoperability between all principals acting in those ecosystems such as persons, organizations,
devices, applications, components, or objects to achieve the common business objectives. As knowledge,
methodologies and terminologies of the domains involved in the business case and represented through
those domains’ ontologies, but also individual contexts, abilities and capabilities are highly different,
they must be shared and adapted in advance or dynamically at runtime, enabling adequate cooperation
[5]
of actors and systems involved. Table 1 summarizes the different interoperability levels .
1) HL7 is a registered trademark of Health Level Seven International. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
2) openEHR is a registered trademark of the openEHR Foundation. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved v

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ISO 23903:2021(E)

Table 1 — Interoperability levels
Information Perspective Organization Perspective
Interoperability
Instances Interoperability Level
Level
Technical Technical plug&play, signal & protocol com- Light-weight interactions
patibility
Structural Simple EDI, envelopes Data sharing
Syntactic Messages and clinical documents with agreed Information sharing
vocabulary
Semantic Advanced messaging with common information Knowledge sharing at IT concept level in
models and terminologies computer-parsable form
Coordination
O rg a n iza t i o n / Common business process Knowledge sharing at business concept level
Service
Agreed service function level cooperation
Knowledge based Multi-domain processes Knowledge sharing at domain level
Cross-domain cooperation
Skills based Individual engagement in multiple domains Knowledge sharing in individual context
Moderated end-user collaboration
0.3  Motivation for the Interoperability and Integration Reference Architecture
Meeting the objectives of improving safety, quality and efficiency of care with ICT support requires
advancing interoperability between computer systems towards a business-process-specific co-
operation of actors representing the different domains participating in the business case. For that
purpose, the agreed domain knowledge, but also the individual and shared context (language, education,
skills, experiences, psychological, social, occupational, environmental aspects, etc.), need to be
represented correctly and formally for integration with the ICT system as part of the business system.
As the domain experts involved describe specific aspects of that business system in their own specific
contexts and using specific terminologies and ontologies, methodologies and frameworks, the resulting
informational representations are often quite inconsistent, requiring a peer-to-peer interoperability
adaptation process. Adapting existing standardized informational representations of domain-specific
use cases to changing contexts or contexts including multiple domains requires another common
harmonized informational representation, resulting in permanent revisions of specifications.
Modelling systems for multi-domain interoperability requires the advancement from the data model,
information model, and ICT domain knowledge perspective to the knowledge perspective of the
[6]
business domains . For achieving the latter, the relevant stakeholders are responsible to define the
provided view of the model as well as the way of structuring and naming the concepts of the problem
space. First capturing key concepts and key relations at a high level of abstraction, different abstraction
levels can be used iteratively. Thereby, the first iteration is performed in a top-down manner to
guarantee the conceptual integrity of the model. This demands meeting design principles such as
[7] [8]
orthogonality, generality, parsimony, and propriety. ISO 30401 defines the requirements for
knowledge management systems in organizations to meet business objectives.
It is impossible to represent the highly complex, highly dynamic, multi-disciplinary/multi-domain
healthcare system by one domain‘s terminology/ontology or – even worse for the reasons mentioned
right before - by exclusively using ICT ontologies and ICT specific representation styles.
The alternative is an abstract, domain-independent representation of systems using Universal Type
[9]
Theory and corresponding logics. The mathematical concept representation using a Meta Reference
[9]
Architecture according to the formal theory of the Barendregt Cube with Parameters in combination
with systems engineering methodologies allows representing any system architecturally (i.e. the
system’s components, their functions and internal as well as external relations) by generically describing
its composition/decomposition and behaviour from the perspectives of all domains of relevance in a
specific business case. A third dimension describes the system’s development process such as evolution
vi © ISO 2021 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 23903:2021(E)

for living systems, manufacturing for technical systems, or a software development process, resulting
in a generic system model or Generic Reference Architecture presented in Figure 1. Details regarding
the dimensions of the model are explained in Clause 5 and Clause 6.
Figure 1 — Generic Reference Architecture model
To represent advanced interoperability and integration settings, different domain-specific
representations are linked to the same real world component. Therefore, an abstract and generic
reference architecture is needed which is able to represent any aspect or domain of interest. For
correctly and formally representing the concepts and relations of the domain-specific subsystems
involved in that business case, those subsystems are represented by their corresponding approved
domain ontologies, resulting in a system-theoretical, architecture-centric, top-level ontology driven
[10][11]
approach . Requirements for top level ontologies are specified in ISO 21838 (all parts). Health
3)
domain ontologies are SNOMED-CT® or specific ontologies such as the Open Biomedical Ontologies
[12] [13]
(OBO), including the Gene Ontology, maintained by the OBO Foundry .
As we can consistently model and compute only systems of reasonable complexity, the Generic Reference
Architecture model (Figure 1) can be used recursively at different granularity levels, so representing,
e.g. the continuum of real-world systems from elementary particles to the universe. The concepts of
the system’s components and their relations are represented in appropriate expressions in natural or
formal languages up to the basic level of primitives. The system analysis or design needs to address
partial systems when considering higher granularity levels of the system in question.
0.4  Technical approach
A system is a composition of interrelated components, ordered to accomplish a specific function or a
set of functions. Systems can be decomposed into subsystems or composed to form super-systems.
There are constructive or structural and behavioural or functional aspects of systems. According to
[14]
IEEE 1471, the architecture of a system is the fundamental organization of that system embodied in
its components, their relationships to each other and to the environment, and the principles guiding its
design and evolution. Rules for selecting and constraining components and functions as well as relations
according to a business case are called policies. Policies define the intended behaviour of a system. For
living systems, factors such as homeostasis, with the attributes of self-organization and self-regulation
as well as growth and development, reproduction, with the associated heredity (structure preservation)
and mutation (structural change), and higher development through selection of best-adapted variants
out of a large number make the description of living systems more complicated than that of technical
[15]
systems .
3) SNOMED CT is the registered trademark of the International Health Terminology Standards Development
Organisation (IHTSDO). This information is given for the convenience of users of this document and does not
constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved vii

---------------------- Page: 7 ----------------------
ISO 23903:2021(E)

In the 1970s and 1980s, a data level interoperability approach was developed by defining the
application and technology agnostic standard data exchange format EDI (electronic data interchange)
in order to transform proprietary data formats into the standard data format and vice versa.
[16]
Thus International Standards arose such as ISO 9735 (EDIFACT), or its healthcare-specific
[17]
pendant ISO/HL7 27931:2009, an application protocol for electronic data exchange in healthcare
environments. This document defines a generic system architecture for knowledge level interoperability.
It allows consistently transforming and interrelating any domain specific subsystem’s structure and
behaviour (e.g. domain specific standards and specifications) by ontologically representing its concepts
and relationships at the real world system component’s level of granularity in the abstract generic
component system. In other words, the domain specific subsystem (e.g. a domain specific standard or
specification) is re-engineered using the Interoperability and Integration Reference Architecture, by
that way providing a standardized interface to that specification. In this way, the methodology offered
in this document maps between domain specific or proprietary systems and their representation as
specification or domain specific standard by transforming them into a standard system architecture
and vice versa. Annex A demonstrates the integration of two domain specific standards by reengineering
[18]
the ISO 13606-1 Reference Model and the HL7® Composite Security and Privacy Domain Analysis
[19]
Model and combining them in an Interoperability and Integration Reference Architecture model
instance. Annex B demonstrates the integration of different communication standards by reengineering
4) 4)
HL7 v3® methodology and creating an adequate HL7 v2® methodology and transforming them into
an Interoperability and Integration Reference Architecture instance. In this way, the Interoperability
and Integration Reference Architecture supports the mutual transformation of those communications
standards for the sake of interoperability of existing solutions. For ontologically representing the
[20]
models, the Communication Standards Ontology (CSO) has been used. Figure 2 correspondingly
presents this standard’s interoperability approach. Annex C demonstrates the integration of different
[21]
standards in the light of ISO 12967(all parts) , while Annex D presents the approach in context of
[22]
ISO 13972 . Finally, Annex E demonstrates the deployment of this document’s Interoperability and
Integration Reference Architecture for the representation and harmonization of alternative reference
architectures.
4) HL7 v3 and HL7 v2 are registered trademarks of Health Level Seven International. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of the products named.
viii © ISO 2021 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 23903:2021(E)

Figure 2 — Overview of this document’s interoperability approach
Bound to the GCM Framework, inter-domain relationships need to happen at the same level of
[23]
granularity . To get there, intra-domain specializations/generalizations are performed.
© ISO 2021 – All rights reserved ix

---------------------- Page: 9 ----------------------
INTERNATIONAL STANDARD ISO 23903:2021(E)
Health informatics — Interoperability and integration
reference architecture — Model and framework
1 Scope
This document enables the advancement of interoperability from the data/information exchange
paradigm to knowledge sharing at decreasing level of abstraction, starting at IT concept level (semantic
coordination) through business domain concept level (agreed service function level cooperation),
domain level (cross-domain cooperation) up to individual context (skills-based end-user collaboration).
The document defines a model and framework for a harmonized representation of existing or intended
systems with a specific focus on ICT-supported business systems. The Interoperability and Integration
Reference Architecture supports ontology harmonization or knowledge harmonization to enable
interoperability between, and integration of, systems, standards and solutions at any level of complexity
without the demand for continuously adapting/revising those specifications. The approach can be
used for analysing, designing, integrating, and running any type of systems. For realizing advanced
interoperability, flexible, scalable, business-controlled, adaptive, knowledge-based, intelligent health
and social ecosystems need to follow a systems-oriented, architecture-centric, ontology-based and
policy-driven approach.
The languages for representing the different views on systems such as ontology languages like
[24] [25] [26]
Common Logic (CL) (ISO/IEC 24707 ) and Web Ontology Language (OWL) – specifically OWL 2
5)
(World Wide Web Consortium (W3C® ), languages for modeling and integrating business processes
6)
like Business Process Modeling Language (BPML) (OMG® ), but also OMG’s Unified Modeling
[27]
Language (UML, also specified as ISO/IEC 19505 ) based representation styles for the different
ISO/IEC 10746 (all parts) views are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10746 (all parts), Information technology — Open distributed processing — Reference model
ISO 22600 (all parts), Health informatics — Privilege management and access control
ISO/IEC 21838 (all parts), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
5) W3C is a registered trademark of the World Wide Web Consortium. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
6) OMG is a registered trademark of The Object Management Group®. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
© ISO 2021 – All rights reserved 1

---------------------- Page: 10 ----------------------
ISO 23903:2021(E)

3.1
architecture
set of rules to define the structure of a system (3.25) and the interrelationships between its parts
[SOURCE: ISO/IEC 10746-2:2009, 6.6, modified — "(of a system)" removed from term.]
3.2
axiom
statement that is taken to be true, to serve as a premise for further reasoning
7)
[SOURCE: ISO/IEC/PRF 21838-1:— , 3.9, modified — Note to entry removed.]
3.3
business viewpoint
viewpoint (3.28) that is concerned with the purpose, scope and policies governing the activities of the
specified ecosystem (3.10)
3.4
class
type
general entity (3.11)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.2, modified — “type” added as second preferred term, note to
entry removed.]
3.5
collection
group of particulars (3.19)
8)
[SOURCE: ISO/IEC/PRF 21838-2:— , 3.4, modified — Notes to entry removed.]
3.6
concept
unit of knowledge created by a unique combination of characteristics
Note 1 to entry: Concepts are not necessarily bound to particular natural languages. They are, however,
influenced by the social or cultural background which often leads to different categorizations.
Note 2 to entry: As a knowledge component, a concept can be specialized and generalized as components can.
[SOURCE: ISO 1087:2019, 3.2.7, modified — Note 2 to entry replaced.]
3.7
definition
representation of a concept by a descriptive statement which serves to differentiate it from related
concepts
[SOURCE: ISO 1087:2019, 3.3.1]
3.8
domain
collection (3.5) of entities (3.11) of interest to a certain community or discipline
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.17, modified — Example and note to entry removed.]
7) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-1:2021.
8) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-2.2:2021.
2 © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

3.9
domain ontology
ontology (3.18) whose terms (3.26) represent classes or types (3.4) and, optionally, certain particulars
(3.19) (called ‘distinguished individuals’) in some domain (3.8)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.18]
3.10
ecosystem
structured systems (3.25) and communities that are governed by general rules
3.11
entity
object
item that is perceivable or conceivable
Note 1 to entry: The terms ‘entity’ and ‘object’ are catch-all terms analogous to ‘something’. In terminology
circles ‘object’ is commonly used in this way. In ontology circles, ‘entity’ and ‘thing’ are commonly used.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.1]
3.12
expression
word or group of words or corresponding symbols that can be used in making an assertion
Note 1 to entry: Expressions are divided into natural language expressions and expressions in a formal language.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.5]
3.13
formal language
language that is machine readable and has well-defined semantics
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.10, modified — Note removed.]
3.14
formal theory
collection (3.5) of definitions (3.7) and axioms (3.2) expressed in a formal language (3.13)
[SOURCE: ISO/IEC/PRF 21838-1: —, 3.11, modified — Note removed.]
3.15
instance
particular (3.19) that instantiates some universal (3.27)
[SOURCE: ISO/IEC/PRF 21838-2:—, 3.6, modified — Example removed.]
3.16
interoperability
ability of a system (3.25) or a product to work with other systems (3.25) or products without special
effort on the part of the customer
Note 1 to entry: Under traditional ICT focus, interoperability is ability of two or more systems or components to
[29]
exchange information and to use the information that has been exchanged .
[SOURCE: IEEE Standards Glossary]
© ISO 2021 – All rights reserved 3

---------------------- Page: 12 ----------------------
ISO 23903:2021(E)

3.17
model
unambiguous, abstract conception of som
...

INTERNATIONAL ISO
STANDARD 23903
First edition
2021-04
Corrected version
2021-07
Health informatics — Interoperability
and integration reference architecture
— Model and framework
Informatique de santé — Architecture de référence d'interopérabilité
et d'intégration — Modèle et cadre
Reference number
ISO 23903:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23903:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 23903:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 5
5 Overview on standard system architecture. 5
6 Interoperability and Integration Reference Architecture for ICT Supported Systems .6
6.1 Interoperability and Integration Reference Architecture domains and granularity levels . 6
6.2 Interoperability and Integration Reference Architecture model for ICT supported
systems . 7
6.3 Interoperability and Integration Reference Architecture framework . 8
6.3.1 Basic requirements . 8
6.3.2 Management of relationships in the Interoperability and Integration
Reference Architecture . 9
6.3.3 Business process modelling using the Interoperability and Integration
Reference Architecture . 9
Annex A (informative) Cross-domain interoperability for security and privacy aware EHR
communication .11
Annex B (informative) Interoperability between different communication standards .13
Annex C (informative) Integration of standards in ISO 12967 (all parts) .15
Annex D (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach in ISO 13972.18
Annex E (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach for the representation and harmonization of alternative
reference architectures .19
Bibliography .21
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ISO 23903:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 251, Health
informatics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
This corrected version of ISO 23903:2021 incorporates the following corrections:
— Figure E.1 has been corrected.
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ISO 23903:2021(E)

Introduction
0.1  Preface
This document supports the integration of a) specifications from different domains with their specific
methodologies, terminologies and ontologies including specific specification style as well as b) systems
based on those specifications. Enabling the use-case-specific identification and consistent, formal
representation including constraints of necessary components with their specific concepts and their
relationships, this document facilitates the deployment of existing standards and systems, the analysis
and improvement of specifications under revision as well as the design of new projects.
This document provides an overview of the Interoperability and Integration Reference Architecture
[1][2]
(first introduced in the 1990s as the Generic Component Model – GCM ), providing scope, justification
and explanation of key concepts and the resulting model and framework. It contains explanatory
material on how this Interoperability and Integration Reference Architecture is interpreted and applied
by its users, who might include standards writers and architects of interoperable systems, but also
systems integrators.
The ongoing organizational, methodological and technological paradigm changes in health and
social care result in health systems transformation toward P5 (personalized, preventive, predictive,
participative precision) systems medicine as fully distributed, highly dynamic, strongly integrated,
multi-disciplinary (or multi-domain) intelligent ecosystems, comprising both structured systems,
[3]
communities governed by rules, and combinations thereof .
0.2  Interoperability levels
Interoperability (see 3.16) has evolved during the last 30 years from structured messaging (e.g. EDI,
1) 2) [4]
HL7® messaging) over sharing concepts [e.g. openEHR® Archetypes, ISO 13940 (system of
concepts to support continuity of care)] – both representing the data/information exchange paradigm
– to cooperation at application level (e.g. Web services). All those solutions focus on information and
communication technologies (ICT) systems interoperability using ICT terminologies and ontologies
for representing data, information, or even concepts and knowledge, thereby distinguishing the three
interoperability levels: a) foundational, b) structural, and c) semantic interoperability.
On the move towards digital health, ICT systems get more closely integrated in the real world business
process. This move requires supporting advanced, knowledge-level and business process focused
interoperability between all principals acting in those ecosystems such as persons, organizations,
devices, applications, components, or objects to achieve the common business objectives. As knowledge,
methodologies and terminologies of the domains involved in the business case and represented through
those domains’ ontologies, but also individual contexts, abilities and capabilities are highly different,
they must be shared and adapted in advance or dynamically at runtime, enabling adequate cooperation
[5]
of actors and systems involved. Table 1 summarizes the different interoperability levels .
1) HL7 is a registered trademark of Health Level Seven International. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
2) openEHR is a registered trademark of the openEHR Foundation. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
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ISO 23903:2021(E)

Table 1 — Interoperability levels
Information Perspective Organization Perspective
Interoperability
Instances Interoperability Level
Level
Technical Technical plug&play, signal & protocol com- Light-weight interactions
patibility
Structural Simple EDI, envelopes Data sharing
Syntactic Messages and clinical documents with agreed Information sharing
vocabulary
Semantic Advanced messaging with common information Knowledge sharing at IT concept level in
models and terminologies computer-parsable form
Coordination
O rg a n iza t i o n / Common business process Knowledge sharing at business concept level
Service
Agreed service function level cooperation
Knowledge based Multi-domain processes Knowledge sharing at domain level
Cross-domain cooperation
Skills based Individual engagement in multiple domains Knowledge sharing in individual context
Moderated end-user collaboration
0.3  Motivation for the Interoperability and Integration Reference Architecture
Meeting the objectives of improving safety, quality and efficiency of care with ICT support requires
advancing interoperability between computer systems towards a business-process-specific co-
operation of actors representing the different domains participating in the business case. For that
purpose, the agreed domain knowledge, but also the individual and shared context (language, education,
skills, experiences, psychological, social, occupational, environmental aspects, etc.), need to be
represented correctly and formally for integration with the ICT system as part of the business system.
As the domain experts involved describe specific aspects of that business system in their own specific
contexts and using specific terminologies and ontologies, methodologies and frameworks, the resulting
informational representations are often quite inconsistent, requiring a peer-to-peer interoperability
adaptation process. Adapting existing standardized informational representations of domain-specific
use cases to changing contexts or contexts including multiple domains requires another common
harmonized informational representation, resulting in permanent revisions of specifications.
Modelling systems for multi-domain interoperability requires the advancement from the data model,
information model, and ICT domain knowledge perspective to the knowledge perspective of the
[6]
business domains . For achieving the latter, the relevant stakeholders are responsible to define the
provided view of the model as well as the way of structuring and naming the concepts of the problem
space. First capturing key concepts and key relations at a high level of abstraction, different abstraction
levels can be used iteratively. Thereby, the first iteration is performed in a top-down manner to
guarantee the conceptual integrity of the model. This demands meeting design principles such as
[7] [8]
orthogonality, generality, parsimony, and propriety. ISO 30401 defines the requirements for
knowledge management systems in organizations to meet business objectives.
It is impossible to represent the highly complex, highly dynamic, multi-disciplinary/multi-domain
healthcare system by one domain‘s terminology/ontology or – even worse for the reasons mentioned
right before - by exclusively using ICT ontologies and ICT specific representation styles.
The alternative is an abstract, domain-independent representation of systems using Universal Type
[9]
Theory and corresponding logics. The mathematical concept representation using a Meta Reference
[9]
Architecture according to the formal theory of the Barendregt Cube with Parameters in combination
with systems engineering methodologies allows representing any system architecturally (i.e. the
system’s components, their functions and internal as well as external relations) by generically describing
its composition/decomposition and behaviour from the perspectives of all domains of relevance in a
specific business case. A third dimension describes the system’s development process such as evolution
vi © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

for living systems, manufacturing for technical systems, or a software development process, resulting
in a generic system model or Generic Reference Architecture presented in Figure 1. Details regarding
the dimensions of the model are explained in Clause 5 and Clause 6.
Figure 1 — Generic Reference Architecture model
To represent advanced interoperability and integration settings, different domain-specific
representations are linked to the same real world component. Therefore, an abstract and generic
reference architecture is needed which is able to represent any aspect or domain of interest. For
correctly and formally representing the concepts and relations of the domain-specific subsystems
involved in that business case, those subsystems are represented by their corresponding approved
domain ontologies, resulting in a system-theoretical, architecture-centric, top-level ontology driven
[10][11]
approach . Requirements for top level ontologies are specified in ISO 21838 (all parts). Health
3)
domain ontologies are SNOMED-CT® or specific ontologies such as the Open Biomedical Ontologies
[12] [13]
(OBO), including the Gene Ontology, maintained by the OBO Foundry .
As we can consistently model and compute only systems of reasonable complexity, the Generic Reference
Architecture model (Figure 1) can be used recursively at different granularity levels, so representing,
e.g. the continuum of real-world systems from elementary particles to the universe. The concepts of
the system’s components and their relations are represented in appropriate expressions in natural or
formal languages up to the basic level of primitives. The system analysis or design needs to address
partial systems when considering higher granularity levels of the system in question.
0.4  Technical approach
A system is a composition of interrelated components, ordered to accomplish a specific function or a
set of functions. Systems can be decomposed into subsystems or composed to form super-systems.
There are constructive or structural and behavioural or functional aspects of systems. According to
[14]
IEEE 1471, the architecture of a system is the fundamental organization of that system embodied in
its components, their relationships to each other and to the environment, and the principles guiding its
design and evolution. Rules for selecting and constraining components and functions as well as relations
according to a business case are called policies. Policies define the intended behaviour of a system. For
living systems, factors such as homeostasis, with the attributes of self-organization and self-regulation
as well as growth and development, reproduction, with the associated heredity (structure preservation)
and mutation (structural change), and higher development through selection of best-adapted variants
out of a large number make the description of living systems more complicated than that of technical
[15]
systems .
3) SNOMED CT is the registered trademark of the International Health Terminology Standards Development
Organisation (IHTSDO). This information is given for the convenience of users of this document and does not
constitute an endorsement by ISO of the product named.
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ISO 23903:2021(E)

In the 1970s and 1980s, a data level interoperability approach was developed by defining the
application and technology agnostic standard data exchange format EDI (electronic data interchange)
in order to transform proprietary data formats into the standard data format and vice versa.
[16]
Thus International Standards arose such as ISO 9735 (EDIFACT), or its healthcare-specific
[17]
pendant ISO/HL7 27931:2009, an application protocol for electronic data exchange in healthcare
environments. This document defines a generic system architecture for knowledge level interoperability.
It allows consistently transforming and interrelating any domain specific subsystem’s structure and
behaviour (e.g. domain specific standards and specifications) by ontologically representing its concepts
and relationships at the real world system component’s level of granularity in the abstract generic
component system. In other words, the domain specific subsystem (e.g. a domain specific standard or
specification) is re-engineered using the Interoperability and Integration Reference Architecture, by
that way providing a standardized interface to that specification. In this way, the methodology offered
in this document maps between domain specific or proprietary systems and their representation as
specification or domain specific standard by transforming them into a standard system architecture
and vice versa. Annex A demonstrates the integration of two domain specific standards by reengineering
[18]
the ISO 13606-1 Reference Model and the HL7® Composite Security and Privacy Domain Analysis
[19]
Model and combining them in an Interoperability and Integration Reference Architecture model
instance. Annex B demonstrates the integration of different communication standards by reengineering
4) 4)
HL7 v3® methodology and creating an adequate HL7 v2® methodology and transforming them into
an Interoperability and Integration Reference Architecture instance. In this way, the Interoperability
and Integration Reference Architecture supports the mutual transformation of those communications
standards for the sake of interoperability of existing solutions. For ontologically representing the
[20]
models, the Communication Standards Ontology (CSO) has been used. Figure 2 correspondingly
presents this standard’s interoperability approach. Annex C demonstrates the integration of different
[21]
standards in the light of ISO 12967(all parts) , while Annex D presents the approach in context of
[22]
ISO 13972 . Finally, Annex E demonstrates the deployment of this document’s Interoperability and
Integration Reference Architecture for the representation and harmonization of alternative reference
architectures.
4) HL7 v3 and HL7 v2 are registered trademarks of Health Level Seven International. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of the products named.
viii © ISO 2021 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 23903:2021(E)

Figure 2 — Overview of this document’s interoperability approach
Bound to the GCM Framework, inter-domain relationships need to happen at the same level of
[23]
granularity . To get there, intra-domain specializations/generalizations are performed.
© ISO 2021 – All rights reserved ix

---------------------- Page: 9 ----------------------
INTERNATIONAL STANDARD ISO 23903:2021(E)
Health informatics — Interoperability and integration
reference architecture — Model and framework
1 Scope
This document enables the advancement of interoperability from the data/information exchange
paradigm to knowledge sharing at decreasing level of abstraction, starting at IT concept level (semantic
coordination) through business domain concept level (agreed service function level cooperation),
domain level (cross-domain cooperation) up to individual context (skills-based end-user collaboration).
The document defines a model and framework for a harmonized representation of existing or intended
systems with a specific focus on ICT-supported business systems. The Interoperability and Integration
Reference Architecture supports ontology harmonization or knowledge harmonization to enable
interoperability between, and integration of, systems, standards and solutions at any level of complexity
without the demand for continuously adapting/revising those specifications. The approach can be
used for analysing, designing, integrating, and running any type of systems. For realizing advanced
interoperability, flexible, scalable, business-controlled, adaptive, knowledge-based, intelligent health
and social ecosystems need to follow a systems-oriented, architecture-centric, ontology-based and
policy-driven approach.
The languages for representing the different views on systems such as ontology languages like
[24] [25] [26]
Common Logic (CL) (ISO/IEC 24707 ) and Web Ontology Language (OWL) – specifically OWL 2
5)
(World Wide Web Consortium (W3C® ), languages for modeling and integrating business processes
6)
like Business Process Modeling Language (BPML) (OMG® ), but also OMG’s Unified Modeling
[27]
Language (UML, also specified as ISO/IEC 19505 ) based representation styles for the different
ISO/IEC 10746 (all parts) views are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10746 (all parts), Information technology — Open distributed processing — Reference model
ISO 22600 (all parts), Health informatics — Privilege management and access control
ISO/IEC 21838 (all parts), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
5) W3C is a registered trademark of the World Wide Web Consortium. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
6) OMG is a registered trademark of The Object Management Group®. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
© ISO 2021 – All rights reserved 1

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ISO 23903:2021(E)

3.1
architecture
set of rules to define the structure of a system (3.25) and the interrelationships between its parts
[SOURCE: ISO/IEC 10746-2:2009, 6.6, modified — "(of a system)" removed from term.]
3.2
axiom
statement that is taken to be true, to serve as a premise for further reasoning
7)
[SOURCE: ISO/IEC/PRF 21838-1:— , 3.9, modified — Note to entry removed.]
3.3
business viewpoint
viewpoint (3.28) that is concerned with the purpose, scope and policies governing the activities of the
specified ecosystem (3.10)
3.4
class
type
general entity (3.11)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.2, modified — “type” added as second preferred term, note to
entry removed.]
3.5
collection
group of particulars (3.19)
8)
[SOURCE: ISO/IEC/PRF 21838-2:— , 3.4, modified — Notes to entry removed.]
3.6
concept
unit of knowledge created by a unique combination of characteristics
Note 1 to entry: Concepts are not necessarily bound to particular natural languages. They are, however,
influenced by the social or cultural background which often leads to different categorizations.
Note 2 to entry: As a knowledge component, a concept can be specialized and generalized as components can.
[SOURCE: ISO 1087:2019, 3.2.7, modified — Note 2 to entry replaced.]
3.7
definition
representation of a concept by a descriptive statement which serves to differentiate it from related
concepts
[SOURCE: ISO 1087:2019, 3.3.1]
3.8
domain
collection (3.5) of entities (3.11) of interest to a certain community or discipline
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.17, modified — Example and note to entry removed.]
7) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-1:2021.
8) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-2.2:2021.
2 © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

3.9
domain ontology
ontology (3.18) whose terms (3.26) represent classes or types (3.4) and, optionally, certain particulars
(3.19) (called ‘distinguished individuals’) in some domain (3.8)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.18]
3.10
ecosystem
structured systems (3.25) and communities that are governed by general rules
3.11
entity
object
item that is perceivable or conceivable
Note 1 to entry: The terms ‘entity’ and ‘object’ are catch-all terms analogous to ‘something’. In terminology
circles ‘object’ is commonly used in this way. In ontology circles, ‘entity’ and ‘thing’ are commonly used.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.1]
3.12
expression
word or group of words or corresponding symbols that can be used in making an assertion
Note 1 to entry: Expressions are divided into natural language expressions and expressions in a formal language.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.5]
3.13
formal language
language that is machine readable and has well-defined semantics
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.10, modified — Note removed.]
3.14
formal theory
collection (3.5) of definitions (3.7) and axioms (3.2) expressed in a formal language (3.13)
[SOURCE: ISO/IEC/PRF 21838-1: —, 3.11, modified — Note removed.]
3.15
instance
particular (3.19) that instantiates some universal (3.27)
[SOURCE: ISO/IEC/PRF 21838-2:—, 3.6, modified — Example removed.]
3.16
interoperability
ability of a system (3.25) or a product to work with other systems (3.25) or products without special
effort on the part of the customer
Note 1 to entry: Under traditional ICT focus, interoperability is ability of two or more systems or components to
[29]
exchange information and to use the information that has been exchanged .
[SOURCE: IEEE Standards Glossary]
© ISO 2021 – All rights reserved 3

---------------------- Page: 12 ----------------------
ISO 23903:2021(E)

3.17
model
unambiguous, abstract conception of som
...

INTERNATIONAL ISO
STANDARD 23903
First edition
2021-04
Corrected version
2021-07
Health informatics — Interoperability
and integration reference architecture
— Model and framework
Informatique de santé — Architecture de référence d'interopérabilité
et d'intégration — Modèle et cadre
Reference number
ISO 23903:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23903:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 23903:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 5
5 Overview on standard system architecture. 5
6 Interoperability and Integration Reference Architecture for ICT Supported Systems .6
6.1 Interoperability and Integration Reference Architecture domains and granularity levels . 6
6.2 Interoperability and Integration Reference Architecture model for ICT supported
systems . 7
6.3 Interoperability and Integration Reference Architecture framework . 8
6.3.1 Basic requirements . 8
6.3.2 Management of relationships in the Interoperability and Integration
Reference Architecture . 9
6.3.3 Business process modelling using the Interoperability and Integration
Reference Architecture . 9
Annex A (informative) Cross-domain interoperability for security and privacy aware EHR
communication .11
Annex B (informative) Interoperability between different communication standards .13
Annex C (informative) Integration of standards in ISO 12967 (all parts) .15
Annex D (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach in ISO 13972.18
Annex E (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach for the representation and harmonization of alternative
reference architectures .19
Bibliography .21
© ISO 2021 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 23903:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 251, Health
informatics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
This corrected version of ISO 23903:2021 incorporates the following corrections:
— Figure E.1 has been corrected.
iv © ISO 2021 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 23903:2021(E)

Introduction
0.1  Preface
This document supports the integration of a) specifications from different domains with their specific
methodologies, terminologies and ontologies including specific specification style as well as b) systems
based on those specifications. Enabling the use-case-specific identification and consistent, formal
representation including constraints of necessary components with their specific concepts and their
relationships, this document facilitates the deployment of existing standards and systems, the analysis
and improvement of specifications under revision as well as the design of new projects.
This document provides an overview of the Interoperability and Integration Reference Architecture
[1][2]
(first introduced in the 1990s as the Generic Component Model – GCM ), providing scope, justification
and explanation of key concepts and the resulting model and framework. It contains explanatory
material on how this Interoperability and Integration Reference Architecture is interpreted and applied
by its users, who might include standards writers and architects of interoperable systems, but also
systems integrators.
The ongoing organizational, methodological and technological paradigm changes in health and
social care result in health systems transformation toward P5 (personalized, preventive, predictive,
participative precision) systems medicine as fully distributed, highly dynamic, strongly integrated,
multi-disciplinary (or multi-domain) intelligent ecosystems, comprising both structured systems,
[3]
communities governed by rules, and combinations thereof .
0.2  Interoperability levels
Interoperability (see 3.16) has evolved during the last 30 years from structured messaging (e.g. EDI,
1) 2) [4]
HL7® messaging) over sharing concepts [e.g. openEHR® Archetypes, ISO 13940 (system of
concepts to support continuity of care)] – both representing the data/information exchange paradigm
– to cooperation at application level (e.g. Web services). All those solutions focus on information and
communication technologies (ICT) systems interoperability using ICT terminologies and ontologies
for representing data, information, or even concepts and knowledge, thereby distinguishing the three
interoperability levels: a) foundational, b) structural, and c) semantic interoperability.
On the move towards digital health, ICT systems get more closely integrated in the real world business
process. This move requires supporting advanced, knowledge-level and business process focused
interoperability between all principals acting in those ecosystems such as persons, organizations,
devices, applications, components, or objects to achieve the common business objectives. As knowledge,
methodologies and terminologies of the domains involved in the business case and represented through
those domains’ ontologies, but also individual contexts, abilities and capabilities are highly different,
they must be shared and adapted in advance or dynamically at runtime, enabling adequate cooperation
[5]
of actors and systems involved. Table 1 summarizes the different interoperability levels .
1) HL7 is a registered trademark of Health Level Seven International. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
2) openEHR is a registered trademark of the openEHR Foundation. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved v

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ISO 23903:2021(E)

Table 1 — Interoperability levels
Information Perspective Organization Perspective
Interoperability
Instances Interoperability Level
Level
Technical Technical plug&play, signal & protocol com- Light-weight interactions
patibility
Structural Simple EDI, envelopes Data sharing
Syntactic Messages and clinical documents with agreed Information sharing
vocabulary
Semantic Advanced messaging with common information Knowledge sharing at IT concept level in
models and terminologies computer-parsable form
Coordination
O rg a n iza t i o n / Common business process Knowledge sharing at business concept level
Service
Agreed service function level cooperation
Knowledge based Multi-domain processes Knowledge sharing at domain level
Cross-domain cooperation
Skills based Individual engagement in multiple domains Knowledge sharing in individual context
Moderated end-user collaboration
0.3  Motivation for the Interoperability and Integration Reference Architecture
Meeting the objectives of improving safety, quality and efficiency of care with ICT support requires
advancing interoperability between computer systems towards a business-process-specific co-
operation of actors representing the different domains participating in the business case. For that
purpose, the agreed domain knowledge, but also the individual and shared context (language, education,
skills, experiences, psychological, social, occupational, environmental aspects, etc.), need to be
represented correctly and formally for integration with the ICT system as part of the business system.
As the domain experts involved describe specific aspects of that business system in their own specific
contexts and using specific terminologies and ontologies, methodologies and frameworks, the resulting
informational representations are often quite inconsistent, requiring a peer-to-peer interoperability
adaptation process. Adapting existing standardized informational representations of domain-specific
use cases to changing contexts or contexts including multiple domains requires another common
harmonized informational representation, resulting in permanent revisions of specifications.
Modelling systems for multi-domain interoperability requires the advancement from the data model,
information model, and ICT domain knowledge perspective to the knowledge perspective of the
[6]
business domains . For achieving the latter, the relevant stakeholders are responsible to define the
provided view of the model as well as the way of structuring and naming the concepts of the problem
space. First capturing key concepts and key relations at a high level of abstraction, different abstraction
levels can be used iteratively. Thereby, the first iteration is performed in a top-down manner to
guarantee the conceptual integrity of the model. This demands meeting design principles such as
[7] [8]
orthogonality, generality, parsimony, and propriety. ISO 30401 defines the requirements for
knowledge management systems in organizations to meet business objectives.
It is impossible to represent the highly complex, highly dynamic, multi-disciplinary/multi-domain
healthcare system by one domain‘s terminology/ontology or – even worse for the reasons mentioned
right before - by exclusively using ICT ontologies and ICT specific representation styles.
The alternative is an abstract, domain-independent representation of systems using Universal Type
[9]
Theory and corresponding logics. The mathematical concept representation using a Meta Reference
[9]
Architecture according to the formal theory of the Barendregt Cube with Parameters in combination
with systems engineering methodologies allows representing any system architecturally (i.e. the
system’s components, their functions and internal as well as external relations) by generically describing
its composition/decomposition and behaviour from the perspectives of all domains of relevance in a
specific business case. A third dimension describes the system’s development process such as evolution
vi © ISO 2021 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 23903:2021(E)

for living systems, manufacturing for technical systems, or a software development process, resulting
in a generic system model or Generic Reference Architecture presented in Figure 1. Details regarding
the dimensions of the model are explained in Clause 5 and Clause 6.
Figure 1 — Generic Reference Architecture model
To represent advanced interoperability and integration settings, different domain-specific
representations are linked to the same real world component. Therefore, an abstract and generic
reference architecture is needed which is able to represent any aspect or domain of interest. For
correctly and formally representing the concepts and relations of the domain-specific subsystems
involved in that business case, those subsystems are represented by their corresponding approved
domain ontologies, resulting in a system-theoretical, architecture-centric, top-level ontology driven
[10][11]
approach . Requirements for top level ontologies are specified in ISO 21838 (all parts). Health
3)
domain ontologies are SNOMED-CT® or specific ontologies such as the Open Biomedical Ontologies
[12] [13]
(OBO), including the Gene Ontology, maintained by the OBO Foundry .
As we can consistently model and compute only systems of reasonable complexity, the Generic Reference
Architecture model (Figure 1) can be used recursively at different granularity levels, so representing,
e.g. the continuum of real-world systems from elementary particles to the universe. The concepts of
the system’s components and their relations are represented in appropriate expressions in natural or
formal languages up to the basic level of primitives. The system analysis or design needs to address
partial systems when considering higher granularity levels of the system in question.
0.4  Technical approach
A system is a composition of interrelated components, ordered to accomplish a specific function or a
set of functions. Systems can be decomposed into subsystems or composed to form super-systems.
There are constructive or structural and behavioural or functional aspects of systems. According to
[14]
IEEE 1471, the architecture of a system is the fundamental organization of that system embodied in
its components, their relationships to each other and to the environment, and the principles guiding its
design and evolution. Rules for selecting and constraining components and functions as well as relations
according to a business case are called policies. Policies define the intended behaviour of a system. For
living systems, factors such as homeostasis, with the attributes of self-organization and self-regulation
as well as growth and development, reproduction, with the associated heredity (structure preservation)
and mutation (structural change), and higher development through selection of best-adapted variants
out of a large number make the description of living systems more complicated than that of technical
[15]
systems .
3) SNOMED CT is the registered trademark of the International Health Terminology Standards Development
Organisation (IHTSDO). This information is given for the convenience of users of this document and does not
constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved vii

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ISO 23903:2021(E)

In the 1970s and 1980s, a data level interoperability approach was developed by defining the
application and technology agnostic standard data exchange format EDI (electronic data interchange)
in order to transform proprietary data formats into the standard data format and vice versa.
[16]
Thus International Standards arose such as ISO 9735 (EDIFACT), or its healthcare-specific
[17]
pendant ISO/HL7 27931:2009, an application protocol for electronic data exchange in healthcare
environments. This document defines a generic system architecture for knowledge level interoperability.
It allows consistently transforming and interrelating any domain specific subsystem’s structure and
behaviour (e.g. domain specific standards and specifications) by ontologically representing its concepts
and relationships at the real world system component’s level of granularity in the abstract generic
component system. In other words, the domain specific subsystem (e.g. a domain specific standard or
specification) is re-engineered using the Interoperability and Integration Reference Architecture, by
that way providing a standardized interface to that specification. In this way, the methodology offered
in this document maps between domain specific or proprietary systems and their representation as
specification or domain specific standard by transforming them into a standard system architecture
and vice versa. Annex A demonstrates the integration of two domain specific standards by reengineering
[18]
the ISO 13606-1 Reference Model and the HL7® Composite Security and Privacy Domain Analysis
[19]
Model and combining them in an Interoperability and Integration Reference Architecture model
instance. Annex B demonstrates the integration of different communication standards by reengineering
4) 4)
HL7 v3® methodology and creating an adequate HL7 v2® methodology and transforming them into
an Interoperability and Integration Reference Architecture instance. In this way, the Interoperability
and Integration Reference Architecture supports the mutual transformation of those communications
standards for the sake of interoperability of existing solutions. For ontologically representing the
[20]
models, the Communication Standards Ontology (CSO) has been used. Figure 2 correspondingly
presents this standard’s interoperability approach. Annex C demonstrates the integration of different
[21]
standards in the light of ISO 12967(all parts) , while Annex D presents the approach in context of
[22]
ISO 13972 . Finally, Annex E demonstrates the deployment of this document’s Interoperability and
Integration Reference Architecture for the representation and harmonization of alternative reference
architectures.
4) HL7 v3 and HL7 v2 are registered trademarks of Health Level Seven International. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of the products named.
viii © ISO 2021 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 23903:2021(E)

Figure 2 — Overview of this document’s interoperability approach
Bound to the GCM Framework, inter-domain relationships need to happen at the same level of
[23]
granularity . To get there, intra-domain specializations/generalizations are performed.
© ISO 2021 – All rights reserved ix

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INTERNATIONAL STANDARD ISO 23903:2021(E)
Health informatics — Interoperability and integration
reference architecture — Model and framework
1 Scope
This document enables the advancement of interoperability from the data/information exchange
paradigm to knowledge sharing at decreasing level of abstraction, starting at IT concept level (semantic
coordination) through business domain concept level (agreed service function level cooperation),
domain level (cross-domain cooperation) up to individual context (skills-based end-user collaboration).
The document defines a model and framework for a harmonized representation of existing or intended
systems with a specific focus on ICT-supported business systems. The Interoperability and Integration
Reference Architecture supports ontology harmonization or knowledge harmonization to enable
interoperability between, and integration of, systems, standards and solutions at any level of complexity
without the demand for continuously adapting/revising those specifications. The approach can be
used for analysing, designing, integrating, and running any type of systems. For realizing advanced
interoperability, flexible, scalable, business-controlled, adaptive, knowledge-based, intelligent health
and social ecosystems need to follow a systems-oriented, architecture-centric, ontology-based and
policy-driven approach.
The languages for representing the different views on systems such as ontology languages like
[24] [25] [26]
Common Logic (CL) (ISO/IEC 24707 ) and Web Ontology Language (OWL) – specifically OWL 2
5)
(World Wide Web Consortium (W3C® ), languages for modeling and integrating business processes
6)
like Business Process Modeling Language (BPML) (OMG® ), but also OMG’s Unified Modeling
[27]
Language (UML, also specified as ISO/IEC 19505 ) based representation styles for the different
ISO/IEC 10746 (all parts) views are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10746 (all parts), Information technology — Open distributed processing — Reference model
ISO 22600 (all parts), Health informatics — Privilege management and access control
ISO/IEC 21838 (all parts), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
5) W3C is a registered trademark of the World Wide Web Consortium. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
6) OMG is a registered trademark of The Object Management Group®. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
© ISO 2021 – All rights reserved 1

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ISO 23903:2021(E)

3.1
architecture
set of rules to define the structure of a system (3.25) and the interrelationships between its parts
[SOURCE: ISO/IEC 10746-2:2009, 6.6, modified — "(of a system)" removed from term.]
3.2
axiom
statement that is taken to be true, to serve as a premise for further reasoning
7)
[SOURCE: ISO/IEC/PRF 21838-1:— , 3.9, modified — Note to entry removed.]
3.3
business viewpoint
viewpoint (3.28) that is concerned with the purpose, scope and policies governing the activities of the
specified ecosystem (3.10)
3.4
class
type
general entity (3.11)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.2, modified — “type” added as second preferred term, note to
entry removed.]
3.5
collection
group of particulars (3.19)
8)
[SOURCE: ISO/IEC/PRF 21838-2:— , 3.4, modified — Notes to entry removed.]
3.6
concept
unit of knowledge created by a unique combination of characteristics
Note 1 to entry: Concepts are not necessarily bound to particular natural languages. They are, however,
influenced by the social or cultural background which often leads to different categorizations.
Note 2 to entry: As a knowledge component, a concept can be specialized and generalized as components can.
[SOURCE: ISO 1087:2019, 3.2.7, modified — Note 2 to entry replaced.]
3.7
definition
representation of a concept by a descriptive statement which serves to differentiate it from related
concepts
[SOURCE: ISO 1087:2019, 3.3.1]
3.8
domain
collection (3.5) of entities (3.11) of interest to a certain community or discipline
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.17, modified — Example and note to entry removed.]
7) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-1:2021.
8) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-2.2:2021.
2 © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

3.9
domain ontology
ontology (3.18) whose terms (3.26) represent classes or types (3.4) and, optionally, certain particulars
(3.19) (called ‘distinguished individuals’) in some domain (3.8)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.18]
3.10
ecosystem
structured systems (3.25) and communities that are governed by general rules
3.11
entity
object
item that is perceivable or conceivable
Note 1 to entry: The terms ‘entity’ and ‘object’ are catch-all terms analogous to ‘something’. In terminology
circles ‘object’ is commonly used in this way. In ontology circles, ‘entity’ and ‘thing’ are commonly used.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.1]
3.12
expression
word or group of words or corresponding symbols that can be used in making an assertion
Note 1 to entry: Expressions are divided into natural language expressions and expressions in a formal language.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.5]
3.13
formal language
language that is machine readable and has well-defined semantics
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.10, modified — Note removed.]
3.14
formal theory
collection (3.5) of definitions (3.7) and axioms (3.2) expressed in a formal language (3.13)
[SOURCE: ISO/IEC/PRF 21838-1: —, 3.11, modified — Note removed.]
3.15
instance
particular (3.19) that instantiates some universal (3.27)
[SOURCE: ISO/IEC/PRF 21838-2:—, 3.6, modified — Example removed.]
3.16
interoperability
ability of a system (3.25) or a product to work with other systems (3.25) or products without special
effort on the part of the customer
Note 1 to entry: Under traditional ICT focus, interoperability is ability of two or more systems or components to
[29]
exchange information and to use the information that has been exchanged .
[SOURCE: IEEE Standards Glossary]
© ISO 2021 – All rights reserved 3

---------------------- Page: 12 ----------------------
ISO 23903:2021(E)

3.17
model
unambiguous, abstract conception of som
...

INTERNATIONAL ISO
STANDARD 23903
First edition
2021-04
Corrected version
2021-07
Health informatics — Interoperability
and integration reference architecture
— Model and framework
Informatique de santé — Architecture de référence d'interopérabilité
et d'intégration — Modèle et cadre
Reference number
ISO 23903:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23903:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 23903:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 5
5 Overview on standard system architecture. 5
6 Interoperability and Integration Reference Architecture for ICT Supported Systems .6
6.1 Interoperability and Integration Reference Architecture domains and granularity levels . 6
6.2 Interoperability and Integration Reference Architecture model for ICT supported
systems . 7
6.3 Interoperability and Integration Reference Architecture framework . 8
6.3.1 Basic requirements . 8
6.3.2 Management of relationships in the Interoperability and Integration
Reference Architecture . 9
6.3.3 Business process modelling using the Interoperability and Integration
Reference Architecture . 9
Annex A (informative) Cross-domain interoperability for security and privacy aware EHR
communication .11
Annex B (informative) Interoperability between different communication standards .13
Annex C (informative) Integration of standards in ISO 12967 (all parts) .15
Annex D (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach in ISO 13972.18
Annex E (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach for the representation and harmonization of alternative
reference architectures .19
Bibliography .21
© ISO 2021 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 23903:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 251, Health
informatics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
This corrected version of ISO 23903:2021 incorporates the following corrections:
— Figure E.1 has been corrected.
iv © ISO 2021 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 23903:2021(E)

Introduction
0.1  Preface
This document supports the integration of a) specifications from different domains with their specific
methodologies, terminologies and ontologies including specific specification style as well as b) systems
based on those specifications. Enabling the use-case-specific identification and consistent, formal
representation including constraints of necessary components with their specific concepts and their
relationships, this document facilitates the deployment of existing standards and systems, the analysis
and improvement of specifications under revision as well as the design of new projects.
This document provides an overview of the Interoperability and Integration Reference Architecture
[1][2]
(first introduced in the 1990s as the Generic Component Model – GCM ), providing scope, justification
and explanation of key concepts and the resulting model and framework. It contains explanatory
material on how this Interoperability and Integration Reference Architecture is interpreted and applied
by its users, who might include standards writers and architects of interoperable systems, but also
systems integrators.
The ongoing organizational, methodological and technological paradigm changes in health and
social care result in health systems transformation toward P5 (personalized, preventive, predictive,
participative precision) systems medicine as fully distributed, highly dynamic, strongly integrated,
multi-disciplinary (or multi-domain) intelligent ecosystems, comprising both structured systems,
[3]
communities governed by rules, and combinations thereof .
0.2  Interoperability levels
Interoperability (see 3.16) has evolved during the last 30 years from structured messaging (e.g. EDI,
1) 2) [4]
HL7® messaging) over sharing concepts [e.g. openEHR® Archetypes, ISO 13940 (system of
concepts to support continuity of care)] – both representing the data/information exchange paradigm
– to cooperation at application level (e.g. Web services). All those solutions focus on information and
communication technologies (ICT) systems interoperability using ICT terminologies and ontologies
for representing data, information, or even concepts and knowledge, thereby distinguishing the three
interoperability levels: a) foundational, b) structural, and c) semantic interoperability.
On the move towards digital health, ICT systems get more closely integrated in the real world business
process. This move requires supporting advanced, knowledge-level and business process focused
interoperability between all principals acting in those ecosystems such as persons, organizations,
devices, applications, components, or objects to achieve the common business objectives. As knowledge,
methodologies and terminologies of the domains involved in the business case and represented through
those domains’ ontologies, but also individual contexts, abilities and capabilities are highly different,
they must be shared and adapted in advance or dynamically at runtime, enabling adequate cooperation
[5]
of actors and systems involved. Table 1 summarizes the different interoperability levels .
1) HL7 is a registered trademark of Health Level Seven International. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
2) openEHR is a registered trademark of the openEHR Foundation. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO 23903:2021(E)

Table 1 — Interoperability levels
Information Perspective Organization Perspective
Interoperability
Instances Interoperability Level
Level
Technical Technical plug&play, signal & protocol com- Light-weight interactions
patibility
Structural Simple EDI, envelopes Data sharing
Syntactic Messages and clinical documents with agreed Information sharing
vocabulary
Semantic Advanced messaging with common information Knowledge sharing at IT concept level in
models and terminologies computer-parsable form
Coordination
O rg a n iza t i o n / Common business process Knowledge sharing at business concept level
Service
Agreed service function level cooperation
Knowledge based Multi-domain processes Knowledge sharing at domain level
Cross-domain cooperation
Skills based Individual engagement in multiple domains Knowledge sharing in individual context
Moderated end-user collaboration
0.3  Motivation for the Interoperability and Integration Reference Architecture
Meeting the objectives of improving safety, quality and efficiency of care with ICT support requires
advancing interoperability between computer systems towards a business-process-specific co-
operation of actors representing the different domains participating in the business case. For that
purpose, the agreed domain knowledge, but also the individual and shared context (language, education,
skills, experiences, psychological, social, occupational, environmental aspects, etc.), need to be
represented correctly and formally for integration with the ICT system as part of the business system.
As the domain experts involved describe specific aspects of that business system in their own specific
contexts and using specific terminologies and ontologies, methodologies and frameworks, the resulting
informational representations are often quite inconsistent, requiring a peer-to-peer interoperability
adaptation process. Adapting existing standardized informational representations of domain-specific
use cases to changing contexts or contexts including multiple domains requires another common
harmonized informational representation, resulting in permanent revisions of specifications.
Modelling systems for multi-domain interoperability requires the advancement from the data model,
information model, and ICT domain knowledge perspective to the knowledge perspective of the
[6]
business domains . For achieving the latter, the relevant stakeholders are responsible to define the
provided view of the model as well as the way of structuring and naming the concepts of the problem
space. First capturing key concepts and key relations at a high level of abstraction, different abstraction
levels can be used iteratively. Thereby, the first iteration is performed in a top-down manner to
guarantee the conceptual integrity of the model. This demands meeting design principles such as
[7] [8]
orthogonality, generality, parsimony, and propriety. ISO 30401 defines the requirements for
knowledge management systems in organizations to meet business objectives.
It is impossible to represent the highly complex, highly dynamic, multi-disciplinary/multi-domain
healthcare system by one domain‘s terminology/ontology or – even worse for the reasons mentioned
right before - by exclusively using ICT ontologies and ICT specific representation styles.
The alternative is an abstract, domain-independent representation of systems using Universal Type
[9]
Theory and corresponding logics. The mathematical concept representation using a Meta Reference
[9]
Architecture according to the formal theory of the Barendregt Cube with Parameters in combination
with systems engineering methodologies allows representing any system architecturally (i.e. the
system’s components, their functions and internal as well as external relations) by generically describing
its composition/decomposition and behaviour from the perspectives of all domains of relevance in a
specific business case. A third dimension describes the system’s development process such as evolution
vi © ISO 2021 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 23903:2021(E)

for living systems, manufacturing for technical systems, or a software development process, resulting
in a generic system model or Generic Reference Architecture presented in Figure 1. Details regarding
the dimensions of the model are explained in Clause 5 and Clause 6.
Figure 1 — Generic Reference Architecture model
To represent advanced interoperability and integration settings, different domain-specific
representations are linked to the same real world component. Therefore, an abstract and generic
reference architecture is needed which is able to represent any aspect or domain of interest. For
correctly and formally representing the concepts and relations of the domain-specific subsystems
involved in that business case, those subsystems are represented by their corresponding approved
domain ontologies, resulting in a system-theoretical, architecture-centric, top-level ontology driven
[10][11]
approach . Requirements for top level ontologies are specified in ISO 21838 (all parts). Health
3)
domain ontologies are SNOMED-CT® or specific ontologies such as the Open Biomedical Ontologies
[12] [13]
(OBO), including the Gene Ontology, maintained by the OBO Foundry .
As we can consistently model and compute only systems of reasonable complexity, the Generic Reference
Architecture model (Figure 1) can be used recursively at different granularity levels, so representing,
e.g. the continuum of real-world systems from elementary particles to the universe. The concepts of
the system’s components and their relations are represented in appropriate expressions in natural or
formal languages up to the basic level of primitives. The system analysis or design needs to address
partial systems when considering higher granularity levels of the system in question.
0.4  Technical approach
A system is a composition of interrelated components, ordered to accomplish a specific function or a
set of functions. Systems can be decomposed into subsystems or composed to form super-systems.
There are constructive or structural and behavioural or functional aspects of systems. According to
[14]
IEEE 1471, the architecture of a system is the fundamental organization of that system embodied in
its components, their relationships to each other and to the environment, and the principles guiding its
design and evolution. Rules for selecting and constraining components and functions as well as relations
according to a business case are called policies. Policies define the intended behaviour of a system. For
living systems, factors such as homeostasis, with the attributes of self-organization and self-regulation
as well as growth and development, reproduction, with the associated heredity (structure preservation)
and mutation (structural change), and higher development through selection of best-adapted variants
out of a large number make the description of living systems more complicated than that of technical
[15]
systems .
3) SNOMED CT is the registered trademark of the International Health Terminology Standards Development
Organisation (IHTSDO). This information is given for the convenience of users of this document and does not
constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved vii

---------------------- Page: 7 ----------------------
ISO 23903:2021(E)

In the 1970s and 1980s, a data level interoperability approach was developed by defining the
application and technology agnostic standard data exchange format EDI (electronic data interchange)
in order to transform proprietary data formats into the standard data format and vice versa.
[16]
Thus International Standards arose such as ISO 9735 (EDIFACT), or its healthcare-specific
[17]
pendant ISO/HL7 27931:2009, an application protocol for electronic data exchange in healthcare
environments. This document defines a generic system architecture for knowledge level interoperability.
It allows consistently transforming and interrelating any domain specific subsystem’s structure and
behaviour (e.g. domain specific standards and specifications) by ontologically representing its concepts
and relationships at the real world system component’s level of granularity in the abstract generic
component system. In other words, the domain specific subsystem (e.g. a domain specific standard or
specification) is re-engineered using the Interoperability and Integration Reference Architecture, by
that way providing a standardized interface to that specification. In this way, the methodology offered
in this document maps between domain specific or proprietary systems and their representation as
specification or domain specific standard by transforming them into a standard system architecture
and vice versa. Annex A demonstrates the integration of two domain specific standards by reengineering
[18]
the ISO 13606-1 Reference Model and the HL7® Composite Security and Privacy Domain Analysis
[19]
Model and combining them in an Interoperability and Integration Reference Architecture model
instance. Annex B demonstrates the integration of different communication standards by reengineering
4) 4)
HL7 v3® methodology and creating an adequate HL7 v2® methodology and transforming them into
an Interoperability and Integration Reference Architecture instance. In this way, the Interoperability
and Integration Reference Architecture supports the mutual transformation of those communications
standards for the sake of interoperability of existing solutions. For ontologically representing the
[20]
models, the Communication Standards Ontology (CSO) has been used. Figure 2 correspondingly
presents this standard’s interoperability approach. Annex C demonstrates the integration of different
[21]
standards in the light of ISO 12967(all parts) , while Annex D presents the approach in context of
[22]
ISO 13972 . Finally, Annex E demonstrates the deployment of this document’s Interoperability and
Integration Reference Architecture for the representation and harmonization of alternative reference
architectures.
4) HL7 v3 and HL7 v2 are registered trademarks of Health Level Seven International. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of the products named.
viii © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

Figure 2 — Overview of this document’s interoperability approach
Bound to the GCM Framework, inter-domain relationships need to happen at the same level of
[23]
granularity . To get there, intra-domain specializations/generalizations are performed.
© ISO 2021 – All rights reserved ix

---------------------- Page: 9 ----------------------
INTERNATIONAL STANDARD ISO 23903:2021(E)
Health informatics — Interoperability and integration
reference architecture — Model and framework
1 Scope
This document enables the advancement of interoperability from the data/information exchange
paradigm to knowledge sharing at decreasing level of abstraction, starting at IT concept level (semantic
coordination) through business domain concept level (agreed service function level cooperation),
domain level (cross-domain cooperation) up to individual context (skills-based end-user collaboration).
The document defines a model and framework for a harmonized representation of existing or intended
systems with a specific focus on ICT-supported business systems. The Interoperability and Integration
Reference Architecture supports ontology harmonization or knowledge harmonization to enable
interoperability between, and integration of, systems, standards and solutions at any level of complexity
without the demand for continuously adapting/revising those specifications. The approach can be
used for analysing, designing, integrating, and running any type of systems. For realizing advanced
interoperability, flexible, scalable, business-controlled, adaptive, knowledge-based, intelligent health
and social ecosystems need to follow a systems-oriented, architecture-centric, ontology-based and
policy-driven approach.
The languages for representing the different views on systems such as ontology languages like
[24] [25] [26]
Common Logic (CL) (ISO/IEC 24707 ) and Web Ontology Language (OWL) – specifically OWL 2
5)
(World Wide Web Consortium (W3C® ), languages for modeling and integrating business processes
6)
like Business Process Modeling Language (BPML) (OMG® ), but also OMG’s Unified Modeling
[27]
Language (UML, also specified as ISO/IEC 19505 ) based representation styles for the different
ISO/IEC 10746 (all parts) views are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10746 (all parts), Information technology — Open distributed processing — Reference model
ISO 22600 (all parts), Health informatics — Privilege management and access control
ISO/IEC 21838 (all parts), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
5) W3C is a registered trademark of the World Wide Web Consortium. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
6) OMG is a registered trademark of The Object Management Group®. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
© ISO 2021 – All rights reserved 1

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ISO 23903:2021(E)

3.1
architecture
set of rules to define the structure of a system (3.25) and the interrelationships between its parts
[SOURCE: ISO/IEC 10746-2:2009, 6.6, modified — "(of a system)" removed from term.]
3.2
axiom
statement that is taken to be true, to serve as a premise for further reasoning
7)
[SOURCE: ISO/IEC/PRF 21838-1:— , 3.9, modified — Note to entry removed.]
3.3
business viewpoint
viewpoint (3.28) that is concerned with the purpose, scope and policies governing the activities of the
specified ecosystem (3.10)
3.4
class
type
general entity (3.11)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.2, modified — “type” added as second preferred term, note to
entry removed.]
3.5
collection
group of particulars (3.19)
8)
[SOURCE: ISO/IEC/PRF 21838-2:— , 3.4, modified — Notes to entry removed.]
3.6
concept
unit of knowledge created by a unique combination of characteristics
Note 1 to entry: Concepts are not necessarily bound to particular natural languages. They are, however,
influenced by the social or cultural background which often leads to different categorizations.
Note 2 to entry: As a knowledge component, a concept can be specialized and generalized as components can.
[SOURCE: ISO 1087:2019, 3.2.7, modified — Note 2 to entry replaced.]
3.7
definition
representation of a concept by a descriptive statement which serves to differentiate it from related
concepts
[SOURCE: ISO 1087:2019, 3.3.1]
3.8
domain
collection (3.5) of entities (3.11) of interest to a certain community or discipline
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.17, modified — Example and note to entry removed.]
7) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-1:2021.
8) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-2.2:2021.
2 © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

3.9
domain ontology
ontology (3.18) whose terms (3.26) represent classes or types (3.4) and, optionally, certain particulars
(3.19) (called ‘distinguished individuals’) in some domain (3.8)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.18]
3.10
ecosystem
structured systems (3.25) and communities that are governed by general rules
3.11
entity
object
item that is perceivable or conceivable
Note 1 to entry: The terms ‘entity’ and ‘object’ are catch-all terms analogous to ‘something’. In terminology
circles ‘object’ is commonly used in this way. In ontology circles, ‘entity’ and ‘thing’ are commonly used.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.1]
3.12
expression
word or group of words or corresponding symbols that can be used in making an assertion
Note 1 to entry: Expressions are divided into natural language expressions and expressions in a formal language.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.5]
3.13
formal language
language that is machine readable and has well-defined semantics
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.10, modified — Note removed.]
3.14
formal theory
collection (3.5) of definitions (3.7) and axioms (3.2) expressed in a formal language (3.13)
[SOURCE: ISO/IEC/PRF 21838-1: —, 3.11, modified — Note removed.]
3.15
instance
particular (3.19) that instantiates some universal (3.27)
[SOURCE: ISO/IEC/PRF 21838-2:—, 3.6, modified — Example removed.]
3.16
interoperability
ability of a system (3.25) or a product to work with other systems (3.25) or products without special
effort on the part of the customer
Note 1 to entry: Under traditional ICT focus, interoperability is ability of two or more systems or components to
[29]
exchange information and to use the information that has been exchanged .
[SOURCE: IEEE Standards Glossary]
© ISO 2021 – All rights reserved 3

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ISO 23903:2021(E)

3.17
model
unambiguous, abstract conception of som
...

INTERNATIONAL ISO
STANDARD 23903
First edition
2021-04
Corrected version
2021-07
Health informatics — Interoperability
and integration reference architecture
— Model and framework
Informatique de santé — Architecture de référence d'interopérabilité
et d'intégration — Modèle et cadre
Reference number
ISO 23903:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23903:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 23903:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 5
5 Overview on standard system architecture. 5
6 Interoperability and Integration Reference Architecture for ICT Supported Systems .6
6.1 Interoperability and Integration Reference Architecture domains and granularity levels . 6
6.2 Interoperability and Integration Reference Architecture model for ICT supported
systems . 7
6.3 Interoperability and Integration Reference Architecture framework . 8
6.3.1 Basic requirements . 8
6.3.2 Management of relationships in the Interoperability and Integration
Reference Architecture . 9
6.3.3 Business process modelling using the Interoperability and Integration
Reference Architecture . 9
Annex A (informative) Cross-domain interoperability for security and privacy aware EHR
communication .11
Annex B (informative) Interoperability between different communication standards .13
Annex C (informative) Integration of standards in ISO 12967 (all parts) .15
Annex D (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach in ISO 13972.18
Annex E (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach for the representation and harmonization of alternative
reference architectures .19
Bibliography .21
© ISO 2021 – All rights reserved iii

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ISO 23903:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 251, Health
informatics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
This corrected version of ISO 23903:2021 incorporates the following corrections:
— Figure E.1 has been corrected.
iv © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

Introduction
0.1  Preface
This document supports the integration of a) specifications from different domains with their specific
methodologies, terminologies and ontologies including specific specification style as well as b) systems
based on those specifications. Enabling the use-case-specific identification and consistent, formal
representation including constraints of necessary components with their specific concepts and their
relationships, this document facilitates the deployment of existing standards and systems, the analysis
and improvement of specifications under revision as well as the design of new projects.
This document provides an overview of the Interoperability and Integration Reference Architecture
[1][2]
(first introduced in the 1990s as the Generic Component Model – GCM ), providing scope, justification
and explanation of key concepts and the resulting model and framework. It contains explanatory
material on how this Interoperability and Integration Reference Architecture is interpreted and applied
by its users, who might include standards writers and architects of interoperable systems, but also
systems integrators.
The ongoing organizational, methodological and technological paradigm changes in health and
social care result in health systems transformation toward P5 (personalized, preventive, predictive,
participative precision) systems medicine as fully distributed, highly dynamic, strongly integrated,
multi-disciplinary (or multi-domain) intelligent ecosystems, comprising both structured systems,
[3]
communities governed by rules, and combinations thereof .
0.2  Interoperability levels
Interoperability (see 3.16) has evolved during the last 30 years from structured messaging (e.g. EDI,
1) 2) [4]
HL7® messaging) over sharing concepts [e.g. openEHR® Archetypes, ISO 13940 (system of
concepts to support continuity of care)] – both representing the data/information exchange paradigm
– to cooperation at application level (e.g. Web services). All those solutions focus on information and
communication technologies (ICT) systems interoperability using ICT terminologies and ontologies
for representing data, information, or even concepts and knowledge, thereby distinguishing the three
interoperability levels: a) foundational, b) structural, and c) semantic interoperability.
On the move towards digital health, ICT systems get more closely integrated in the real world business
process. This move requires supporting advanced, knowledge-level and business process focused
interoperability between all principals acting in those ecosystems such as persons, organizations,
devices, applications, components, or objects to achieve the common business objectives. As knowledge,
methodologies and terminologies of the domains involved in the business case and represented through
those domains’ ontologies, but also individual contexts, abilities and capabilities are highly different,
they must be shared and adapted in advance or dynamically at runtime, enabling adequate cooperation
[5]
of actors and systems involved. Table 1 summarizes the different interoperability levels .
1) HL7 is a registered trademark of Health Level Seven International. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
2) openEHR is a registered trademark of the openEHR Foundation. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved v

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ISO 23903:2021(E)

Table 1 — Interoperability levels
Information Perspective Organization Perspective
Interoperability
Instances Interoperability Level
Level
Technical Technical plug&play, signal & protocol com- Light-weight interactions
patibility
Structural Simple EDI, envelopes Data sharing
Syntactic Messages and clinical documents with agreed Information sharing
vocabulary
Semantic Advanced messaging with common information Knowledge sharing at IT concept level in
models and terminologies computer-parsable form
Coordination
O rg a n iza t i o n / Common business process Knowledge sharing at business concept level
Service
Agreed service function level cooperation
Knowledge based Multi-domain processes Knowledge sharing at domain level
Cross-domain cooperation
Skills based Individual engagement in multiple domains Knowledge sharing in individual context
Moderated end-user collaboration
0.3  Motivation for the Interoperability and Integration Reference Architecture
Meeting the objectives of improving safety, quality and efficiency of care with ICT support requires
advancing interoperability between computer systems towards a business-process-specific co-
operation of actors representing the different domains participating in the business case. For that
purpose, the agreed domain knowledge, but also the individual and shared context (language, education,
skills, experiences, psychological, social, occupational, environmental aspects, etc.), need to be
represented correctly and formally for integration with the ICT system as part of the business system.
As the domain experts involved describe specific aspects of that business system in their own specific
contexts and using specific terminologies and ontologies, methodologies and frameworks, the resulting
informational representations are often quite inconsistent, requiring a peer-to-peer interoperability
adaptation process. Adapting existing standardized informational representations of domain-specific
use cases to changing contexts or contexts including multiple domains requires another common
harmonized informational representation, resulting in permanent revisions of specifications.
Modelling systems for multi-domain interoperability requires the advancement from the data model,
information model, and ICT domain knowledge perspective to the knowledge perspective of the
[6]
business domains . For achieving the latter, the relevant stakeholders are responsible to define the
provided view of the model as well as the way of structuring and naming the concepts of the problem
space. First capturing key concepts and key relations at a high level of abstraction, different abstraction
levels can be used iteratively. Thereby, the first iteration is performed in a top-down manner to
guarantee the conceptual integrity of the model. This demands meeting design principles such as
[7] [8]
orthogonality, generality, parsimony, and propriety. ISO 30401 defines the requirements for
knowledge management systems in organizations to meet business objectives.
It is impossible to represent the highly complex, highly dynamic, multi-disciplinary/multi-domain
healthcare system by one domain‘s terminology/ontology or – even worse for the reasons mentioned
right before - by exclusively using ICT ontologies and ICT specific representation styles.
The alternative is an abstract, domain-independent representation of systems using Universal Type
[9]
Theory and corresponding logics. The mathematical concept representation using a Meta Reference
[9]
Architecture according to the formal theory of the Barendregt Cube with Parameters in combination
with systems engineering methodologies allows representing any system architecturally (i.e. the
system’s components, their functions and internal as well as external relations) by generically describing
its composition/decomposition and behaviour from the perspectives of all domains of relevance in a
specific business case. A third dimension describes the system’s development process such as evolution
vi © ISO 2021 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 23903:2021(E)

for living systems, manufacturing for technical systems, or a software development process, resulting
in a generic system model or Generic Reference Architecture presented in Figure 1. Details regarding
the dimensions of the model are explained in Clause 5 and Clause 6.
Figure 1 — Generic Reference Architecture model
To represent advanced interoperability and integration settings, different domain-specific
representations are linked to the same real world component. Therefore, an abstract and generic
reference architecture is needed which is able to represent any aspect or domain of interest. For
correctly and formally representing the concepts and relations of the domain-specific subsystems
involved in that business case, those subsystems are represented by their corresponding approved
domain ontologies, resulting in a system-theoretical, architecture-centric, top-level ontology driven
[10][11]
approach . Requirements for top level ontologies are specified in ISO 21838 (all parts). Health
3)
domain ontologies are SNOMED-CT® or specific ontologies such as the Open Biomedical Ontologies
[12] [13]
(OBO), including the Gene Ontology, maintained by the OBO Foundry .
As we can consistently model and compute only systems of reasonable complexity, the Generic Reference
Architecture model (Figure 1) can be used recursively at different granularity levels, so representing,
e.g. the continuum of real-world systems from elementary particles to the universe. The concepts of
the system’s components and their relations are represented in appropriate expressions in natural or
formal languages up to the basic level of primitives. The system analysis or design needs to address
partial systems when considering higher granularity levels of the system in question.
0.4  Technical approach
A system is a composition of interrelated components, ordered to accomplish a specific function or a
set of functions. Systems can be decomposed into subsystems or composed to form super-systems.
There are constructive or structural and behavioural or functional aspects of systems. According to
[14]
IEEE 1471, the architecture of a system is the fundamental organization of that system embodied in
its components, their relationships to each other and to the environment, and the principles guiding its
design and evolution. Rules for selecting and constraining components and functions as well as relations
according to a business case are called policies. Policies define the intended behaviour of a system. For
living systems, factors such as homeostasis, with the attributes of self-organization and self-regulation
as well as growth and development, reproduction, with the associated heredity (structure preservation)
and mutation (structural change), and higher development through selection of best-adapted variants
out of a large number make the description of living systems more complicated than that of technical
[15]
systems .
3) SNOMED CT is the registered trademark of the International Health Terminology Standards Development
Organisation (IHTSDO). This information is given for the convenience of users of this document and does not
constitute an endorsement by ISO of the product named.
© ISO 2021 – All rights reserved vii

---------------------- Page: 7 ----------------------
ISO 23903:2021(E)

In the 1970s and 1980s, a data level interoperability approach was developed by defining the
application and technology agnostic standard data exchange format EDI (electronic data interchange)
in order to transform proprietary data formats into the standard data format and vice versa.
[16]
Thus International Standards arose such as ISO 9735 (EDIFACT), or its healthcare-specific
[17]
pendant ISO/HL7 27931:2009, an application protocol for electronic data exchange in healthcare
environments. This document defines a generic system architecture for knowledge level interoperability.
It allows consistently transforming and interrelating any domain specific subsystem’s structure and
behaviour (e.g. domain specific standards and specifications) by ontologically representing its concepts
and relationships at the real world system component’s level of granularity in the abstract generic
component system. In other words, the domain specific subsystem (e.g. a domain specific standard or
specification) is re-engineered using the Interoperability and Integration Reference Architecture, by
that way providing a standardized interface to that specification. In this way, the methodology offered
in this document maps between domain specific or proprietary systems and their representation as
specification or domain specific standard by transforming them into a standard system architecture
and vice versa. Annex A demonstrates the integration of two domain specific standards by reengineering
[18]
the ISO 13606-1 Reference Model and the HL7® Composite Security and Privacy Domain Analysis
[19]
Model and combining them in an Interoperability and Integration Reference Architecture model
instance. Annex B demonstrates the integration of different communication standards by reengineering
4) 4)
HL7 v3® methodology and creating an adequate HL7 v2® methodology and transforming them into
an Interoperability and Integration Reference Architecture instance. In this way, the Interoperability
and Integration Reference Architecture supports the mutual transformation of those communications
standards for the sake of interoperability of existing solutions. For ontologically representing the
[20]
models, the Communication Standards Ontology (CSO) has been used. Figure 2 correspondingly
presents this standard’s interoperability approach. Annex C demonstrates the integration of different
[21]
standards in the light of ISO 12967(all parts) , while Annex D presents the approach in context of
[22]
ISO 13972 . Finally, Annex E demonstrates the deployment of this document’s Interoperability and
Integration Reference Architecture for the representation and harmonization of alternative reference
architectures.
4) HL7 v3 and HL7 v2 are registered trademarks of Health Level Seven International. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of the products named.
viii © ISO 2021 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 23903:2021(E)

Figure 2 — Overview of this document’s interoperability approach
Bound to the GCM Framework, inter-domain relationships need to happen at the same level of
[23]
granularity . To get there, intra-domain specializations/generalizations are performed.
© ISO 2021 – All rights reserved ix

---------------------- Page: 9 ----------------------
INTERNATIONAL STANDARD ISO 23903:2021(E)
Health informatics — Interoperability and integration
reference architecture — Model and framework
1 Scope
This document enables the advancement of interoperability from the data/information exchange
paradigm to knowledge sharing at decreasing level of abstraction, starting at IT concept level (semantic
coordination) through business domain concept level (agreed service function level cooperation),
domain level (cross-domain cooperation) up to individual context (skills-based end-user collaboration).
The document defines a model and framework for a harmonized representation of existing or intended
systems with a specific focus on ICT-supported business systems. The Interoperability and Integration
Reference Architecture supports ontology harmonization or knowledge harmonization to enable
interoperability between, and integration of, systems, standards and solutions at any level of complexity
without the demand for continuously adapting/revising those specifications. The approach can be
used for analysing, designing, integrating, and running any type of systems. For realizing advanced
interoperability, flexible, scalable, business-controlled, adaptive, knowledge-based, intelligent health
and social ecosystems need to follow a systems-oriented, architecture-centric, ontology-based and
policy-driven approach.
The languages for representing the different views on systems such as ontology languages like
[24] [25] [26]
Common Logic (CL) (ISO/IEC 24707 ) and Web Ontology Language (OWL) – specifically OWL 2
5)
(World Wide Web Consortium (W3C® ), languages for modeling and integrating business processes
6)
like Business Process Modeling Language (BPML) (OMG® ), but also OMG’s Unified Modeling
[27]
Language (UML, also specified as ISO/IEC 19505 ) based representation styles for the different
ISO/IEC 10746 (all parts) views are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10746 (all parts), Information technology — Open distributed processing — Reference model
ISO 22600 (all parts), Health informatics — Privilege management and access control
ISO/IEC 21838 (all parts), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
5) W3C is a registered trademark of the World Wide Web Consortium. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
6) OMG is a registered trademark of The Object Management Group®. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
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ISO 23903:2021(E)

3.1
architecture
set of rules to define the structure of a system (3.25) and the interrelationships between its parts
[SOURCE: ISO/IEC 10746-2:2009, 6.6, modified — "(of a system)" removed from term.]
3.2
axiom
statement that is taken to be true, to serve as a premise for further reasoning
7)
[SOURCE: ISO/IEC/PRF 21838-1:— , 3.9, modified — Note to entry removed.]
3.3
business viewpoint
viewpoint (3.28) that is concerned with the purpose, scope and policies governing the activities of the
specified ecosystem (3.10)
3.4
class
type
general entity (3.11)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.2, modified — “type” added as second preferred term, note to
entry removed.]
3.5
collection
group of particulars (3.19)
8)
[SOURCE: ISO/IEC/PRF 21838-2:— , 3.4, modified — Notes to entry removed.]
3.6
concept
unit of knowledge created by a unique combination of characteristics
Note 1 to entry: Concepts are not necessarily bound to particular natural languages. They are, however,
influenced by the social or cultural background which often leads to different categorizations.
Note 2 to entry: As a knowledge component, a concept can be specialized and generalized as components can.
[SOURCE: ISO 1087:2019, 3.2.7, modified — Note 2 to entry replaced.]
3.7
definition
representation of a concept by a descriptive statement which serves to differentiate it from related
concepts
[SOURCE: ISO 1087:2019, 3.3.1]
3.8
domain
collection (3.5) of entities (3.11) of interest to a certain community or discipline
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.17, modified — Example and note to entry removed.]
7) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-1:2021.
8) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-2.2:2021.
2 © ISO 2021 – All rights reserved

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ISO 23903:2021(E)

3.9
domain ontology
ontology (3.18) whose terms (3.26) represent classes or types (3.4) and, optionally, certain particulars
(3.19) (called ‘distinguished individuals’) in some domain (3.8)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.18]
3.10
ecosystem
structured systems (3.25) and communities that are governed by general rules
3.11
entity
object
item that is perceivable or conceivable
Note 1 to entry: The terms ‘entity’ and ‘object’ are catch-all terms analogous to ‘something’. In terminology
circles ‘object’ is commonly used in this way. In ontology circles, ‘entity’ and ‘thing’ are commonly used.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.1]
3.12
expression
word or group of words or corresponding symbols that can be used in making an assertion
Note 1 to entry: Expressions are divided into natural language expressions and expressions in a formal language.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.5]
3.13
formal language
language that is machine readable and has well-defined semantics
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.10, modified — Note removed.]
3.14
formal theory
collection (3.5) of definitions (3.7) and axioms (3.2) expressed in a formal language (3.13)
[SOURCE: ISO/IEC/PRF 21838-1: —, 3.11, modified — Note removed.]
3.15
instance
particular (3.19) that instantiates some universal (3.27)
[SOURCE: ISO/IEC/PRF 21838-2:—, 3.6, modified — Example removed.]
3.16
interoperability
ability of a system (3.25) or a product to work with other systems (3.25) or products without special
effort on the part of the customer
Note 1 to entry: Under traditional ICT focus, interoperability is ability of two or more systems or components to
[29]
exchange information and to use the information that has been exchanged .
[SOURCE: IEEE Standards Glossary]
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ISO 23903:2021(E)

3.17
model
unambiguous, abstract conception of som
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ISO 23903:2021 (F)
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ISO 23903:2021 (F)
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Avant-propos . iv
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Introduction. v
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1 Domaine d'application . 1
2 Références normatives . 1
3 Termes et définitions . 1
4 Abréviations . 5
5 Vue d'ensemble de l'architecture de système standard . 5
6 Architecture de référence d'interopérabilité et d'intégration pour les systèmes pris
en charge par les technologies de l'information et de la communication . 6
6.1 Domaines et niveaux de granularité de l'Architecture de référence
d'interopérabilité et d'intégration . 6
6.2 Modèle d'Architecture de référence d'interopérabilité et d'intégration pour les
systèmes pris en charge par les technologies de l'information et de la
communication . 7
6.3 Cadre de l'Architecture de référence d'interopérabilité et d'intégration . 9
6.3.1 Exigences de base . 9
6.3.2 Gestion des relations dans l'Architecture de référence d'interopérabilité et
d'intégration. 9
6.3.3 Modélisation du processus métier à l'aide de l'Architecture de référence
d'interopérabilité et d'intégration . 11
Annexe A (informative) Interopérabilité inter-domaines pour une communication du
Dossier informatisé de santé (DIS) respectueuse de la sécurité et de la vie privée . 14
Annexe B (informative) Interopérabilité entre différentes normes de communications . 18
Annexe C (informative) Intégration des normes dans l'ISO 12967 (toutes les parties) . 20
Annexe D (informative) Déploiement de l'approche d'Architecture de référence
d'interopérabilité et d'intégration dans l'ISO 13972 . 25
Annexe E (Informative) Déploiement de l'approche d'Architecture de référence
d'interopérabilité et d'intégration pour la représentation et l'harmonisation des
architectures de référence alternatives . 27
Bibliographie . 30
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ISO 23903:2021 (F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes Formatted: French (Switzerland)
nationaux de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en
général confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit
de faire partie du comité technique créé à cet effet. Les organisations internationales, gouvernementales
et non gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore
étroitement avec la Commission électrotechnique internationale (IEC) en ce qui concerne la
normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier, de prendre note des différents Formatted: French (Switzerland)
critères d'approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2
Formatted: Underline, Font color: Blue
(voir www.iso.org/directives).
Formatted: Underline, Font color: Blue
L'attention est attirée sur le fait que certains des éléments du présent document peuvent faire l'objet de
Formatted: French (Switzerland)
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable de
ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant les
références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de l'élaboration
du document sont indiqués dans l'Introduction et/ou dans la liste des déclarations de brevets reçues par
l'ISO (voir www.iso.org/brevets). Formatted: Underline, Font color: Blue
Formatted: Underline, Font color: Blue
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
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pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions Formatted: Adjust space between Latin and Asian text, Adjust
space between Asian text and numbers
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion
de l'ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles
techniques au commerce (OTC), voir le lien suivant : www.iso.org/iso/fr/avant-propos. Formatted: Underline, Font color: Blue
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Le présent document a été élaboré par le comité technique ISO/TC 215, Informatique de santé, en
Formatted: Underline, Font color: Blue
collaboration avec le Comité Technique comité technique CEN/TC 251, Informatique de santé, du Comité
Formatted: French (Switzerland)
européen de normalisation (CEN),) conformément à l'Accordl’Accord de coopération technique entre
Formatted: Font: Italic
l'ISOl’ISO et le CEN (Accord de Vienne).
Formatted: Font: Italic
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
Formatted: Font: Italic
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes
Formatted: French (Switzerland)
se trouve à l’adresse www.iso.org/fr/members.html.
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Pattern: Clear
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ISO 23903:2021 (F)
Introduction
0.1  Préface
Le présent document accompagne l'intégration a) de spécifications de différents domaines, avec leurs
méthodologies, terminologies et ontologies spécifiques, y compris les règles de rédaction propres aux
spécifications, ainsi que b) de systèmes basés sur ces spécifications. En permettant une identification
spécifique aux cas d'utilisation, ainsi qu'une représentation cohérente et formelle, y compris les
contraintes de composants nécessaires avec leurs concepts spécifiques et leurs relations, le présent
document facilite le déploiement de normes et de systèmes existants, l'analyse et l'amélioration des
spécifications en cours de révision, ainsi que la conception de nouveaux projets.
Le présent document offre une vue d'ensemble de l'Architecture de référence d'interopérabilité et
[1][2]
d'intégration (introduite dans les années 90 sous le nom de Modèle de Composant Générique – GCM ),
en donnant le domaine d'application, la justification et l'explication des concepts clés ainsi que le modèle
et le cadre qui en découlent. Elle explique la façon d'interpréter cette Architecture de référence
d'interopérabilité et d'intégration et la manière dont elle peut être utilisée, en particulier, par les auteurs
de normes et les architectes de systèmes interopérables, mais aussi par les intégrateurs de systèmes.
Les changements radicaux actuellement en cours concernant l'organisation, la méthodologie et la
technologie dans le domaine des soins de santé et des soins sociaux donnent lieu à une transformation
des systèmes de santé vers une médecine de systèmes P5 (médecine personnalisée, préventive,
prédictive, participative et pertinente) sous la forme d'écosystèmes pleinement répartis, extrêmement
dynamiques, hautement intégrés, pluridisciplinaires (ou multi-domaines) intelligents, qui comprennent
[3]
des systèmes structurés, des communautés régies par des règles, et leurs combinaisons .
0.2  Niveaux d'interopérabilité
L'interopérabilité (voir 3.16) a évolué au cours des 30 dernières années, des messages structurés (par
1 2
exemple EDI, messagerie HL7® ) à des concepts de partage [par exemple archétypes openEHR® ,
[4]
ISO 13940 (système de concepts en appui de la continuité des soins)] – tous deux représentant le
paradigme d'échange de données/d'informations, puis à la coopération au niveau des applications
(par exemple, services Web). Toutes ces solutions sont axées sur l'interopérabilité des systèmes de
technologies de l'information et de la communication (TIC) qui utilisent les terminologies et les
ontologies TIC pour représenter des données, des informations, ou même des concepts et des
connaissances, établissant ainsi une distinction entre les trois niveaux d'interopérabilité : a) primaire, b)
structurel et c) sémantique.
Dans la transition vers les soins de santé numérique, les systèmes TIC deviennent plus étroitement Formatted: Don't keep with next, Don't keep lines together
intégrés dans les processus métier réels. Cette transition nécessite de promouvoir une interopérabilité
de pointe au niveau des connaissances et axée sur les processus métier entre tous les acteurs clés de ces
écosystèmes, tels que les personnes, les organismes, les dispositifs, les applications, les composants ou
les objets afin d'atteindre les objectifs métier communs. Étant donné que les connaissances, les
méthodologies et les terminologies des domaines impliqués dans l'analyse de cas et représentées par les
ontologies de ces domaines, mais aussi les contextes, facultés et capacités individuels, sont très

1
HL7 est une marque déposée de Health Level Seven International. Cette information est donnée par souci de Formatted: French (Switzerland)
commodité à l'intention des utilisateurs du présent document et ne saurait constituer un engagement de la part de
l'ISO quant au produit désigné.
Formatted: French (Switzerland)
2
openEHR est une marque déposée de la Fondation openEHR. Cette information est donnée par souci de commodité
Formatted: Font: Bold
à l'intention des utilisateurs du présent document et ne saurait constituer un engagement de la part de l'ISO quant
au produit désigné. Formatted: Space After: 0 pt
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ISO 23903:2021 (F)
différentes, elles doivent être partagées et adaptées à l'avance ou dynamiquement pendant l'exécution,
pour permettre une coopération adéquate des acteurs et des systèmes en jeu. Une synthèse des différents
[5]
niveaux d'interopérabilité est donnée dans le Tableau 1 .
Tableau 1 — Niveaux d'interopérabilité Formatted: None, Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers
Perspective d'information Perspective d'organisation
Niveau
Instances Niveau d'interopérabilité
d'interopérabilité
Technique Prêt à l'emploi technique, compatibilité Interactions légères Formatted: Left
signal et protocole
Structurel EDI simple, enveloppes Partage de données
Formatted: Left
Syntaxique Messages et documents cliniques avec Partage d'informations Formatted: Left
vocabulaire convenu
Sémantique Messagerie de pointe avec modèles Partage des connaissances au niveau du
Formatted: Left
d'informations et terminologies communs concept TI sous forme analysable
informatiquement
Coordination
Organisation/ Processus métier commun Partage des connaissances au niveau du Formatted: Left
Service concept métier
Coopération convenue au niveau des
fonctions de service
Basé sur les Processus multi-domaines Partage des connaissances au niveau du
Formatted: Left
connaissances domaine
Coopération inter-domaines
Basé sur les Engagement individuel dans des domaines Partage des connaissances dans un Formatted: Left
compétences multiples contexte individuel
Collaboration dirigée entre utilisateurs
finaux
0.3  Motivation de l'Architecture de référence d'interopérabilité et d'intégration
Répondre aux objectifs d'amélioration de la sécurité, de la qualité et de l'efficacité des soins au moyen Formatted: Don't keep with next, Don't keep lines together
des TIC exige une interopérabilité avancée entre les systèmes informatiques allant dans le sens d'une
coopération spécifique aux processus métier des acteurs représentant les différents domaines
participant au dossier de décision. À cette fin, il est nécessaire que la connaissance du domaine concerné,
mais également le contexte individuel et partagé (langue, éducation, compétences, expérience, aspects
psychologiques, sociaux professionnels et environnementaux, etc.), soient représentés correctement et
de manière formelle pour être intégrés dans le système de TIC dans le cadre d'un système professionnel.
Étant donné que les experts de différents domaines impliqués décrivent les aspects spécifiques de ce
système professionnel dans leurs propres contextes spécifiques, utilisant leurs terminologies, ontologies,
méthodologies et cadres conceptuels spécifiques, les représentations d'informations qui en résultent
sont souvent relativement incohérentes, ce qui exige un processus d'adaptation de l'interopérabilité de
poste à poste. L'adaptation de représentations d'informations normalisées existantes pour des cas
d'utilisation spécifiques à des domaines, à des contextes changeants ou incluant de multiples domaines
exige une autre représentation d'informations harmonisée commune, ce qui entraîne des révisions
permanentes des spécifications.
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ISO 23903:2021 (F)
Les systèmes de modélisation pour une interopérabilité multi-domaine nécessitent de passer de la
perspective des connaissances en matière de modèle de données, de modèle d'information et du domaine
[6]
des TIC à la perspective des connaissances des domaines d'activité . À cette fin, les parties prenantes
concernées doivent définir la vue fournie du modèle, ainsi que la manière de structurer et de nommer les
concepts de l'espace de problème. En capturant au préalable les concepts clés et les relations clés à un
niveau d'abstraction élevé, il est possible d'utiliser différents niveaux d'abstraction de façon itérative.
Ainsi, la première itération est effectuée de manière descendante pour garantir l'intégrité conceptuelle
du modèle. Cela nécessite de respecter des principes de conception tels que l'orthogonalité, la généralité,
[[7]] [8]
la parcimonie et la propriété. . L'ISO 30401 définit les exigences relatives aux systèmes de
management des connaissances dans les organismes afin de répondre aux objectifs métier.
Il est impossible de représenter le système de soins de santé hautement complexe et dynamique,
pluridisciplinaire et multi-domaine au moyen de la terminologie/ontologie d'un seul domaine ou, pire
encore, pour les raisons mentionnées ci-dessus, en utilisant exclusivement des ontologies des TIC et des
styles de représentation spécifiques.
Une variante est une représentation abstraite, indépendante du domaine, des systèmes utilisant la
[9]
théorie universelle des types et les logiques correspondantes. La représentation du concept
mathématique à l'aide d'une Architecture de méta-référence suivant la théorie formelle du Cube de
[9]
Barendregt avec Paramètres combinée à des méthodologies d'ingénierie des systèmes permet de
représenter l'architecture de tout système (c'est-à-dire les composants du système, leurs fonctions et
leurs relations internes comme externes) par le biais de la description générique de sa
composition/décomposition et de son comportement du point de vue de tous les domaines pertinents
dans un dossier de décision. Une troisième dimension décrit le processus de développement du système,
comme l'évolution pour les systèmes vivants, la fabrication pour les systèmes techniques, ou un
processus de développement de logiciel, donnant un modèle de système générique ou une Architecture
de référence générique illustrée à la Figure 1. Les détails concernant les dimensions du modèle sont
expliqués à l'Article 5 et à l'Article 6.

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ISO 23903:2021 (F)

Figure 1 — Modèle d'architecture de référence générique
Pour représenter les paramètres avancés d'interopérabilité et d'intégration, différentes représentations
spécifiques à un domaine sont associées au même composant réel. En conséquence, une architecture de
référence abstraite et générique capable de représenter tout aspect ou domaine présentant un intérêt est
nécessaire. Afin de représenter de façon formelle et correcte les concepts et relations des sous-systèmes
propres à un domaine impliqués dans ce dossier de décision, ces sous-systèmes sont représentés par
leurs ontologies de domaine approuvées correspondantes, débouchant sur une approche du système
[10][11]
théorique, centrée sur l'architecture et contrôlée par des ontologies de niveau supérieur . Les
exigences relatives aux ontologies de niveau supérieur sont spécifiées dans l'ISO 21838 (toutes les
3
parties). les ontologies du domaine de santé sont CT SNOMED® ou des ontologies spécifiques comme
[12] [13]
les Open Biomedical Ontologies (OBO) , y compris Gene Ontology, maintenues par OBO Foundry .
Vu que nous ne pouvons modéliser et calculer que des systèmes raisonnablement complexes, le modèle
d'architecture de référence générique (Figure 1) peut être utilisé de manière récursive à différents
niveaux de granularité, représentant ainsi, par exemple, la continuité de systèmes réels, depuis les
particules élémentaires jusqu'à l'univers. Les concepts des composants du système et leurs relations sont
représentés par des expressions appropriées dans les langues naturelles ou formelles jusqu'au niveau de
base des primitives. L'analyse ou la conception du système doit prendre en compte les systèmes partiels
lorsque sont envisagés les niveaux de granularité supérieurs du système en question.

Formatted: French (Switzerland)
3
CT SNOMED est une marque déposée de l'International Health Terminology Standards Development Organisation
Formatted: Font: Bold
(IHTSDO). Cette information est donnée par souci de commodité à l'intention des utilisateurs du présent document
et ne saurait constituer un engagement de la part de l'ISO quant au produit désigné. Formatted: Space After: 0 pt
© ISO 2021 – Tous droits réservés
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ISO 23903:2021 (F)
0.4  Approche technique
Un système est une composition de composants interdépendants ordonnés de façon à accomplir une Formatted: Don't keep with next, Don't keep lines together
fonction ou un ensemble de fonctions spécifiques. Les systèmes peuvent être décomposés en sous-
systèmes ou regroupés pour former des super-systèmes. Les systèmes ont des aspects constructifs ou
[14]
structurels et comportementaux ou fonctionnels. Suivant l'IEEE 1471 , l'architecture d'un système est
l'organisation fondamentale de ce système telle qu'elle est concrétisée par ses composants, leurs
relations entre eux et avec l'environnement, et par les principes qui orientent sa conception et son
évolution. Les règles de sélection et de restriction des composants et des fonctions, ainsi que des relations
conformément à un dossier de décision sont appelées des politiques. Les politiques définissent le
comportement attendu d'un système. Dans le cas des systèmes vivants, des facteurs comme
l'homéostasie, avec les attributs d'auto--organisation et d'autorégulation, ainsi que de croissance et de
développement, de reproduction, avec l'hérédité (préservation des structures) et la mutation
(changements de structure) associées, et un développement supérieur par la sélection des variantes les
plus adaptées parmi beaucoup d'autres, rendent la description de systèmes vivants plus compliquée que
[15]
celle de systèmes techniques .
Dans les années 70 et 80, une démarche d'interopérabilité au niveau des données a été développée en
définissant le format EDI (electronic data interchange, échange de données électroniques) d'échange de
données standard, indépendant des applications et des technologies, afin de transformer des formats de
données propriétaires en format de données standard et vice versa. C'est pour cela qu'ont été élaborées
[16]
des Normes internationales telles que l'ISO 9735 (EDIFACT) , ou son pendant spécifique aux soins de
[17]
santé, l'ISO/HL7 27931:2009 , un protocole d'application pour l'échange de données électroniques Formatted: Default Paragraph Font
dans les environnements de soins. Le présent document définit une architecture générique de système
Formatted: Default Paragraph Font
pour l'interopérabilité des niveaux de connaissance. Cette architecture permet de transformer et
Formatted: Default Paragraph Font
d'interrelier de façon cohérente la structure et le comportement de tout sous-système spécifique à un
domaine (par exemple, les normes et spécifications propres à un domaine) en représentant de façon
ontologique ses concepts et ses relations au niveau de granularité du composant système réel dans le
système de composants génériques abstraits. En d'autres termes, le sous-système spécifique au domaine
(par exemple, une norme ou une spécification propre au domaine) est réorganisé au moyen de
l'Architecture de référence d'interopérabilité et d'intégration, produisant ainsi une interface normalisée
avec cette spécification. Ainsi, la méthodologie proposée dans le présent document établit une
correspondance entre les systèmes spécifiques à un domaine ou propriétaires et leur représentation sous
forme de spécification ou de norme spécifique à un domaine en les transformant en architecture de
système standard et vice versa. L'Annexe A démontre l'intégration de deux normes spécifiques à un
[18]
domaine en réorganisant l'ISO 13606-1 Modèle de Référence et la norme HL7® Composite Security Formatted: Default Paragraph Font
[19]
and Privacy Domain Analysis Model et en les combinant dans une instance de modèle d'Architecture
de référence d'interopérabilité et d'intégration. L'Annexe B démontre l'intégration de différentes normes
4
de communication en réorganisant la méthodologie HL7 v3® et en créant une méthodologie adéquate
4)
HL7 v2® , et en les transformant en une instance d'Architecture de référence d'interopérabilité et
d'intégration. Ainsi, l'Architecture de référence d'interopérabilité et d'intégration prend en charge la
Formatted: std_docPartNumber
transformation mutuelle de ces normes de communications pour assurer l'interopérabilité des solutions
Formatted: Not Superscript/ Subscript
[20]
existantes. La Communication Standards Ontology (CSO) a été utilisée pour la représentation
Formatted: French (Switzerland)
ontologique des modèles. La démarche d'interopérabilité de cette norme est présentée à la Figure 2.
[21] Form
...

NORME ISO
INTERNATIONALE 23903
Première édition
2021-04
Informatique de santé — Architecture
de référence d'interopérabilité et
d'intégration — Modèle et cadre
Health informatics — Interoperability and integration reference
architecture – Model and framework
Numéro de référence
ISO 23903:2021(F)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23903:2021(F)

DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2021
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
Case postale 401 • Ch. de Blandonnet 8
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Tél.: +41 22 749 01 11
E-mail: copyright@iso.org
Web: www.iso.org
Publié en Suisse
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ISO 23903:2021(F)

Sommaire Page
Avant-propos .iv
Introduction .v
1 Domaine d'application . 1
2 Références normatives . 1
3 Termes et définitions . 2
4 Abréviations . 5
5 Vue d'ensemble de l'architecture de système standard . 5
6 Architecture de référence d'interopérabilité et d'intégration pour les systèmes pris
en charge par les technologies de l'information et de la communication .6
6.1 Domaines et niveaux de granularité de l'Architecture de référence
d'interopérabilité et d'intégration. 6
6.2 Modèle d'Architecture de référence d'interopérabilité et d'intégration pour
les systèmes pris en charge par les technologies de l'information et de la communication 7
6.3 Cadre de l'Architecture de référence d'interopérabilité et d'intégration . 8
6.3.1 Exigences de base . 8
6.3.2 Gestion des relations dans l'Architecture de référence d'interopérabilité et
d'intégration . 9
6.3.3 Modélisation du processus métier à l'aide de l'Architecture de référence
d'interopérabilité et d'intégration .10
Annexe A (informative) Interopérabilité inter-domaines pour une communication
du Dossier informatisé de santé (DIS) respectueuse de la sécurité et de la vie privée .12
Annexe B (informative) Interopérabilité entre différentes normes de communications .15
Annexe C (informative) Intégration des normes dans l'ISO 12967 (toutes les parties) .17
Annexe D (informative) Déploiement de l'approche d'Architecture de référence
d'interopérabilité et d'intégration dans l'ISO 13972 .21
Annexe E (informative) Déploiement de l'approche d'Architecture de référence
d'interopérabilité et d'intégration pour la représentation et l'harmonisation des
architectures de référence alternatives .22
Bibliographie .25
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ISO 23903:2021(F)

Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes
nationaux de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est
en général confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l'ISO participent également aux travaux.
L'ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier, de prendre note des différents
critères d'approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir www
.iso .org/ directives).
L'attention est attirée sur le fait que certains des éléments du présent document peuvent faire l'objet de
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant
les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l'élaboration du document sont indiqués dans l'Introduction et/ou dans la liste des déclarations de
brevets reçues par l'ISO (voir www .iso .org/ brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion
de l'ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles
techniques au commerce (OTC), voir www .iso .org/ avant -propos.
Le présent document a été élaboré par le comité technique ISO/TC 215, Informatique de santé, en
collaboration avec le comité technique CEN/TC 251, Informatique de santé, du Comité européen de
normalisation (CEN) conformément à l’Accord de coopération technique entre l’ISO et le CEN (Accord
de Vienne).
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes
se trouve à l’adresse www .iso .org/ fr/ members .html.
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ISO 23903:2021(F)

Introduction
0.1  Préface
Le présent document accompagne l'intégration a) de spécifications de différents domaines, avec leurs
méthodologies, terminologies et ontologies spécifiques, y compris les règles de rédaction propres aux
spécifications, ainsi que b) de systèmes basés sur ces spécifications. En permettant une identification
spécifique aux cas d'utilisation, ainsi qu'une représentation cohérente et formelle, y compris les
contraintes de composants nécessaires avec leurs concepts spécifiques et leurs relations, le présent
document facilite le déploiement de normes et de systèmes existants, l'analyse et l'amélioration des
spécifications en cours de révision, ainsi que la conception de nouveaux projets.
Le présent document offre une vue d'ensemble de l'Architecture de référence d'interopérabilité et
[1]
d'intégration (introduite dans les années 90 sous le nom de Modèle de Composant Générique – GCM
[2]
), en donnant le domaine d'application, la justification et l'explication des concepts clés ainsi que le
modèle et le cadre qui en découlent. Elle explique la façon d'interpréter cette Architecture de référence
d'interopérabilité et d'intégration et la manière dont elle peut être utilisée, en particulier, par les auteurs
de normes et les architectes de systèmes interopérables, mais aussi par les intégrateurs de systèmes.
Les changements radicaux actuellement en cours concernant l'organisation, la méthodologie et la
technologie dans le domaine des soins de santé et des soins sociaux donnent lieu à une transformation
des systèmes de santé vers une médecine de systèmes P5 (médecine personnalisée, préventive,
prédictive, participative et pertinente) sous la forme d'écosystèmes pleinement répartis, extrêmement
dynamiques, hautement intégrés, pluridisciplinaires (ou multi-domaines) intelligents, qui comprennent
[3]
des systèmes structurés, des communautés régies par des règles, et leurs combinaisons .
0.2  Niveaux d'interopérabilité
L'interopérabilité (voir 3.16) a évolué au cours des 30 dernières années, des messages structurés (par
1) 2)
exemple EDI, messagerie HL7® ) à des concepts de partage [par exemple archétypes openEHR® ,
[4]
ISO 13940 (système de concepts en appui de la continuité des soins)] – tous deux représentant le
paradigme d'échange de données/d'informations, puis à la coopération au niveau des applications
(par exemple, services Web). Toutes ces solutions sont axées sur l'interopérabilité des systèmes
de technologies de l'information et de la communication (TIC) qui utilisent les terminologies et
les ontologies TIC pour représenter des données, des informations, ou même des concepts et des
connaissances, établissant ainsi une distinction entre les trois niveaux d'interopérabilité: a) primaire,
b) structurel et c) sémantique.
Dans la transition vers les soins de santé numérique, les systèmes TIC deviennent plus étroitement
intégrés dans les processus métier réels. Cette transition nécessite de promouvoir une interopérabilité
de pointe au niveau des connaissances et axée sur les processus métier entre tous les acteurs clés de
ces écosystèmes, tels que les personnes, les organismes, les dispositifs, les applications, les composants
ou les objets afin d'atteindre les objectifs métier communs. Étant donné que les connaissances, les
méthodologies et les terminologies des domaines impliqués dans l'analyse de cas et représentées par
les ontologies de ces domaines, mais aussi les contextes, facultés et capacités individuels, sont très
différentes, elles doivent être partagées et adaptées à l'avance ou dynamiquement pendant l'exécution,
pour permettre une coopération adéquate des acteurs et des systèmes en jeu. Une synthèse des
[5]
différents niveaux d'interopérabilité est donnée dans le Tableau 1 .
1) HL7 est une marque déposée de Health Level Seven International. Cette information est donnée par souci de
commodité à l'intention des utilisateurs du présent document et ne saurait constituer un engagement de la part de
l'ISO quant au produit désigné.
2) openEHR est une marque déposée de la Fondation openEHR. Cette information est donnée par souci de
commodité à l'intention des utilisateurs du présent document et ne saurait constituer un engagement de la part de
l'ISO quant au produit désigné.
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ISO 23903:2021(F)

Tableau 1 — Niveaux d'interopérabilité
Perspective d'information Perspective d'organisation
Niveau
Instances Niveau d'interopérabilité
d'interopérabilité
Technique Prêt à l'emploi technique, compatibilité Interactions légères
signal et protocole
Structurel EDI simple, enveloppes Partage de données
Syntaxique Messages et documents cliniques avec Partage d'informations
vocabulaire convenu
Sémantique Messagerie de pointe avec modèles Partage des connaissances au niveau
d'informations et terminologies communs du concept TI sous forme analysable
informatiquement
Coordination
Organisation/ Processus métier commun Partage des connaissances au niveau du
Service concept métier
Coopération convenue au niveau des
fonctions de service
Basé sur les Processus multi-domaines Partage des connaissances au niveau du
connaissances domaine
Coopération inter-domaines
Basé sur les Engagement individuel dans des domaines Partage des connaissances dans un
compétences multiples contexte individuel
Collaboration dirigée entre utilisateurs
finaux
0.3  Motivation de l'Architecture de référence d'interopérabilité et d'intégration
Répondre aux objectifs d'amélioration de la sécurité, de la qualité et de l'efficacité des soins au moyen
des TIC exige une interopérabilité avancée entre les systèmes informatiques allant dans le sens
d'une coopération spécifique aux processus métier des acteurs représentant les différents domaines
participant au dossier de décision. À cette fin, il est nécessaire que la connaissance du domaine concerné,
mais également le contexte individuel et partagé (langue, éducation, compétences, expérience, aspects
psychologiques, sociaux professionnels et environnementaux, etc.), soient représentés correctement et
de manière formelle pour être intégrés dans le système de TIC dans le cadre d'un système professionnel.
Étant donné que les experts de différents domaines impliqués décrivent les aspects spécifiques de
ce système professionnel dans leurs propres contextes spécifiques, utilisant leurs terminologies,
ontologies, méthodologies et cadres conceptuels spécifiques, les représentations d'informations
qui en résultent sont souvent relativement incohérentes, ce qui exige un processus d'adaptation
de l'interopérabilité de poste à poste. L'adaptation de représentations d'informations normalisées
existantes pour des cas d'utilisation spécifiques à des domaines, à des contextes changeants ou incluant
de multiples domaines exige une autre représentation d'informations harmonisée commune, ce qui
entraîne des révisions permanentes des spécifications.
Les systèmes de modélisation pour une interopérabilité multi-domaine nécessitent de passer de
la perspective des connaissances en matière de modèle de données, de modèle d'information et du
[6]
domaine des TIC à la perspective des connaissances des domaines d'activité . À cette fin, les parties
prenantes concernées doivent définir la vue fournie du modèle, ainsi que la manière de structurer et de
nommer les concepts de l'espace de problème. En capturant au préalable les concepts clés et les relations
clés à un niveau d'abstraction élevé, il est possible d'utiliser différents niveaux d'abstraction de façon
itérative. Ainsi, la première itération est effectuée de manière descendante pour garantir l'intégrité
conceptuelle du modèle. Cela nécessite de respecter des principes de conception tels que l'orthogonalité,
[7] [8]
la généralité, la parcimonie et la propriété . L'ISO 30401 définit les exigences relatives aux systèmes
de management des connaissances dans les organismes afin de répondre aux objectifs métier.
Il est impossible de représenter le système de soins de santé hautement complexe et dynamique,
pluridisciplinaire et multi-domaine au moyen de la terminologie/ontologie d'un seul domaine ou, pire
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ISO 23903:2021(F)

encore, pour les raisons mentionnées ci-dessus, en utilisant exclusivement des ontologies des TIC et des
styles de représentation spécifiques.
Une variante est une représentation abstraite, indépendante du domaine, des systèmes utilisant
[9]
la théorie universelle des types et les logiques correspondantes. La représentation du concept
mathématique à l'aide d'une Architecture de méta-référence suivant la théorie formelle du Cube de
[9]
Barendregt avec Paramètres combinée à des méthodologies d'ingénierie des systèmes permet de
représenter l'architecture de tout système (c'est-à-dire les composants du système, leurs fonctions et
leurs relations internes comme externes) par le biais de la description générique de sa composition/
décomposition et de son comportement du point de vue de tous les domaines pertinents dans un
dossier de décision. Une troisième dimension décrit le processus de développement du système, comme
l'évolution pour les systèmes vivants, la fabrication pour les systèmes techniques, ou un processus de
développement de logiciel, donnant un modèle de système générique ou une Architecture de référence
générique illustrée à la Figure 1. Les détails concernant les dimensions du modèle sont expliqués à
l'Article 5 et à l'Article 6.
Figure 1 — Modèle d'architecture de référence générique
Pour représenter les paramètres avancés d'interopérabilité et d'intégration, différentes représentations
spécifiques à un domaine sont associées au même composant réel. En conséquence, une architecture de
référence abstraite et générique capable de représenter tout aspect ou domaine présentant un intérêt est
nécessaire. Afin de représenter de façon formelle et correcte les concepts et relations des sous-systèmes
propres à un domaine impliqués dans ce dossier de décision, ces sous-systèmes sont représentés par
leurs ontologies de domaine approuvées correspondantes, débouchant sur une approche du système
[10][11]
théorique, centrée sur l'architecture et contrôlée par des ontologies de niveau supérieur . Les
exigences relatives aux ontologies de niveau supérieur sont spécifiées dans l'ISO 21838 (toutes les
3)
parties). les ontologies du domaine de santé sont CT SNOMED® ou des ontologies spécifiques comme
[12] [13]
les Open Biomedical Ontologies (OBO) , y compris Gene Ontology, maintenues par OBO Foundry .
Vu que nous ne pouvons modéliser et calculer que des systèmes raisonnablement complexes, le modèle
d'architecture de référence générique (Figure 1) peut être utilisé de manière récursive à différents
niveaux de granularité, représentant ainsi, par exemple, la continuité de systèmes réels, depuis les
particules élémentaires jusqu'à l'univers. Les concepts des composants du système et leurs relations
sont représentés par des expressions appropriées dans les langues naturelles ou formelles jusqu'au
niveau de base des primitives. L'analyse ou la conception du système doit prendre en compte les
systèmes partiels lorsque sont envisagés les niveaux de granularité supérieurs du système en question.
3) CT SNOMED est une marque déposée de l'International Health Terminology Standards Development Organisation
(IHTSDO). Cette information est donnée par souci de commodité à l'intention des utilisateurs du présent document
et ne saurait constituer un engagement de la part de l'ISO quant au produit désigné.
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ISO 23903:2021(F)

0.4  Approche technique
Un système est une composition de composants interdépendants ordonnés de façon à accomplir une
fonction ou un ensemble de fonctions spécifiques. Les systèmes peuvent être décomposés en sous-
systèmes ou regroupés pour former des super-systèmes. Les systèmes ont des aspects constructifs ou
[14]
structurels et comportementaux ou fonctionnels. Suivant l'IEEE 1471 , l'architecture d'un système
est l'organisation fondamentale de ce système telle qu'elle est concrétisée par ses composants, leurs
relations entre eux et avec l'environnement, et par les principes qui orientent sa conception et son
évolution. Les règles de sélection et de restriction des composants et des fonctions, ainsi que des
relations conformément à un dossier de décision sont appelées des politiques. Les politiques définissent
le comportement attendu d'un système. Dans le cas des systèmes vivants, des facteurs comme
l'homéostasie, avec les attributs d'auto-organisation et d'autorégulation, ainsi que de croissance
et de développement, de reproduction, avec l'hérédité (préservation des structures) et la mutation
(changements de structure) associées, et un développement supérieur par la sélection des variantes
les plus adaptées parmi beaucoup d'autres, rendent la description de systèmes vivants plus compliquée
[15]
que celle de systèmes techniques .
Dans les années 70 et 80, une démarche d'interopérabilité au niveau des données a été développée en
définissant le format EDI (electronic data interchange, échange de données électroniques) d'échange de
données standard, indépendant des applications et des technologies, afin de transformer des formats de
données propriétaires en format de données standard et vice versa. C'est pour cela qu'ont été élaborées
[16]
des Normes internationales telles que l'ISO 9735 (EDIFACT) , ou son pendant spécifique aux soins
[17]
de santé, l'ISO/HL7 27931:2009 , un protocole d'application pour l'échange de données électroniques
dans les environnements de soins. Le présent document définit une architecture générique de système
pour l'interopérabilité des niveaux de connaissance. Cette architecture permet de transformer et
d'interrelier de façon cohérente la structure et le comportement de tout sous-système spécifique à un
domaine (par exemple, les normes et spécifications propres à un domaine) en représentant de façon
ontologique ses concepts et ses relations au niveau de granularité du composant système réel dans
le système de composants génériques abstraits. En d'autres termes, le sous-système spécifique au
domaine (par exemple, une norme ou une spécification propre au domaine) est réorganisé au moyen de
l'Architecture de référence d'interopérabilité et d'intégration, produisant ainsi une interface normalisée
avec cette spécification. Ainsi, la méthodologie proposée dans le présent document établit une
correspondance entre les systèmes spécifiques à un domaine ou propriétaires et leur représentation
sous forme de spécification ou de norme spécifique à un domaine en les transformant en architecture
de système standard et vice versa. L'Annexe A démontre l'intégration de deux normes spécifiques à un
[18]
domaine en réorganisant l'ISO 13606-1 Modèle de Référence et la norme HL7® Composite Security
[19]
and Privacy Domain Analysis Model et en les combinant dans une instance de modèle d'Architecture
de référence d'interopérabilité et d'intégration. L'Annexe B démontre l'intégration de différentes normes
4)
de communication en réorganisant la méthodologie HL7 v3® et en créant une méthodologie adéquate
4)
HL7 v2® , et en les transformant en une instance d'Architecture de référence d'interopérabilité et
d'intégration. Ainsi, l'Architecture de référence d'interopérabilité et d'intégration prend en charge la
transformation mutuelle de ces normes de communications pour assurer l'interopérabilité des solutions
[20]
existantes. La Communication Standards Ontology (CSO) a été utilisée pour la représentation
ontologique des modèles. La démarche d'interopérabilité de cette norme est présentée à la Figure 2.
[21]
L'Annexe C démontre l'intégration de différentes normes d'après l'ISO 12967 (toutes les parties) ,
5) [22]
alors que l'Annexe D présente la démarche dans le contexte de l'ISO 13972 . Enfin, l'Annexe E
démontre la mise en œuvre de l'Architecture de référence d'interopérabilité et d'intégration du présent
document pour la représentation et l'harmonisation des architecture de référence alternatives.
4) HL7 v3 et HL7 v2 sont des marques déposées de Health Level Seven International. Cette information est donnée
par souci de commodité à l'intention des utilisateurs du présent document et ne saurait constituer un engagement
de la part de l'ISO quant au produit désigné.
5) En cours d'élaboration. Stade au moment de la publication: ISO/DIS 13972:2020.
viii © ISO 2021 – Tous droits réservés

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ISO 23903:2021(F)

Figure 2 — Vue d'ensemble de la démarche d'interopérabilité du présent document
Il est nécessaire que les relations interdomaines, liées au cadre GCM, se produisent au même niveau de
[23]
détails . Pour cela, des spécialisations/généralisations intradomaines sont effectuées.
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NORME INTERNATIONALE ISO 23903:2021(F)
Informatique de santé — Architecture de référence
d'interopérabilité et d'intégration — Modèle et cadre
1 Domaine d'application
Le présent document permet de faire progresser l'interopérabilité depuis le paradigme d'échange de
données/d'informations vers le partage des connaissances à un niveau d'abstraction de moins en moins
élevé, en commençant au niveau des concepts TI (coordination sémantique) en passant par le niveau
des concepts de domaine d'activité (coopération convenue au niveau des fonctions de service), le niveau
du domaine (coopération inter-domaines) jusqu'au contexte individuel (collaboration entre utilisateurs
finaux fondée sur les compétences). Le présent document définit un modèle et un cadre pour une
représentation harmonisée de systèmes existants ou prévus, portant plus particulièrement sur les
systèmes professionnels pris en charge par les technologies de l'information et de la communication.
L'architecture de référence d'interopérabilité et d'intégration prend en charge l'harmonisation
ontologique ou l'harmonisation des connaissances afin de permettre l'interopérabilité entre, et
l'intégration des, systèmes, normes et solutions à tout niveau de complexité sans exiger d'adapter
ou réviser en continu ces spécifications. Cette démarche peut être utilisée pour analyser, concevoir,
intégrer et faire fonctionner tout type de systèmes. Pour arriver à une interopérabilité avancée, il est
nécessaire que des écosystèmes de santé et sociaux flexibles, évolutifs, contrôlés par les activités,
adaptables, basés sur les connaissances et intelligents suivent une démarche orientée systèmes, centrée
sur l'architecture, basée sur l'ontologie et dictée par une politique.
Les langages utilisés pour représenter les différentes vues des systèmes, comme les langages d'ontologie
[24] [25]
tels que Common Logic (CL) (ISO/IEC 24707 ) et Web Ontology Language (OWL) – spécifiquement
[26] 6)
OWL 2 (World Wide Web Consortium, W3C® ), les langages de modélisation et d'intégration de
7)
processus professionnels tels que Business Process Modeling Language (BPML) (OMG® ), mais
[27]
également Unified Modeling Language d'OMG (UML, également spécifié comme l'ISO/IEC 19505 )
basés sur les styles de représentation pour les différentes vues de l' ISO/IEC 10746 (toutes les parties)
ne relèvent pas du domaine d'application du présent document.
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu’ils constituent, pour tout ou partie de leur
contenu, des exigences du présent document. Pour les références datées, seule l’édition citée s’applique.
Pour les références non datées, la dernière édition du document de référence s'applique (y compris les
éventuels amendements).
ISO/IEC 10746 (toutes les parties), Technologies de l’information — Traitement réparti ouvert — Modèle
de référence: Architecture
ISO 22600 (toutes les parties), Informatique de santé — Gestion de privilèges et contrôle d’accès
ISO/IEC 21838 (toutes les parties), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
6) W3C est une marque déposée du World Wide Web Consortium. Cette information est donnée par souci de
commodité à l'intention des utilisateurs du présent document et ne saurait constituer un engagement de la part de
l'ISO quant au produit désigné.
7) OMG est une marque déposée de l'OMG (Object Management Group®). Cette information est donnée par souci
de commodité à l'intention des utilisateurs du présent document et ne saurait constituer un engagement de la part
de l'ISO quant au produit désigné.
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ISO 23903:2021(F)

3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s’appliquent.
L’ISO et l’IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en
normalisation, consultables aux adresses suivantes:
— ISO Online browsing platform: disponible à l’adresse https:// www .iso .org/ obp
— IEC Electropedia: disponible à l’adresse http:// www .electropedia .org/
3.1
architecture
ensemble de règles destinées à définir la structure des systèmes (3.25), et les relations entre leurs
différentes parties
[SOURCE: ISO/IEC 10746-2:2009, 6
...

INTERNATIONAL ISO
STANDARD 23903
First edition
Health informatics — Interoperability
and integration reference architecture
– Model and framework
Informatique de santé — Architecture de référence d'interopérabilité
et d'intégration — Modèle et cadre
PROOF/ÉPREUVE
Reference number
ISO 23903:2021(E)
©
ISO 2021

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ISO 23903:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
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ISO 23903:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 5
5 Overview on standard system architecture. 5
6 Interoperability and Integration Reference Architecture for ICT Supported Systems .6
6.1 Interoperability and Integration Reference Architecture domains and granularity levels . 6
6.2 Interoperability and Integration Reference Architecture model for ICT supported
systems . 7
6.3 Interoperability and Integration Reference Architecture framework . 8
6.3.1 Basic requirements . 8
6.3.2 Management of relationships in the Interoperability and Integration
Reference Architecture . 9
6.3.3 Business process modelling using the Interoperability and Integration
Reference Architecture . 9
Annex A (informative) Cross-domain interoperability for security and privacy aware EHR
communication .11
Annex B (informative) Interoperability between different communication standards .13
Annex C (informative) Integration of Standards in ISO 12967 (all parts) .15
Annex D (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach in ISO 13972.18
Annex E (informative) Deployment of the Interoperability and Integration Reference
Architecture Approach for the Representation and Harmonization of Alternative
Reference Architectures .19
Bibliography .21
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ISO 23903:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 251, Health
informatics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO 23903:2021(E)

Introduction
0.1  Preface
This document supports the integration of a) specifications from different domains with their specific
methodologies, terminologies and ontologies including specific specification style as well as b) systems
based on those specifications. Enabling the use-case-specific identification and consistent, formal
representation including constraints of necessary components with their specific concepts and their
relationships, this document facilitates the deployment of existing standards and systems, the analysis
and improvement of specifications under revision as well as the design of new projects.
This document provides an overview of the Interoperability and Integration Reference Architecture
[1][2]
(first introduced in the 1990s as the Generic Component Model – GCM ), providing scope, justification
and explanation of key concepts and the resulting model and framework. It contains explanatory
material on how this Interoperability and Integration Reference Architecture is interpreted and applied
by its users, who might include standards writers and architects of interoperable systems, but also
systems integrators.
The ongoing organizational, methodological and technological paradigm changes in health and
social care result in health systems transformation toward P5 (personalized, preventive, predictive,
participative precision) systems medicine as fully distributed, highly dynamic, strongly integrated,
multi-disciplinary (or multi-domain) intelligent ecosystems, comprising both structured systems,
[3]
communities governed by rules, and combinations thereof .
0.2  Interoperability levels
Interoperability (see 3.16) has evolved during the last 30 years from structured messaging (e.g. EDI,
1) 2) [4]
HL7® messaging) over sharing concepts [e.g. openEHR® Archetypes, ISO 13940 (system of
concepts to support continuity of care)] – both representing the data/information exchange paradigm
– to cooperation at application level (e.g. Web services). All those solutions focus on information and
communication technologies (ICT) systems interoperability using ICT terminologies and ontologies
for representing data, information, or even concepts and knowledge, thereby distinguishing the three
interoperability levels: a) foundational, b) structural, and c) semantic interoperability.
On the move towards digital health, ICT systems get more closely integrated in the real world business
process. This move requires supporting advanced, knowledge-level and business process focused
interoperability between all principals acting in those ecosystems such as persons, organizations,
devices, applications, components, or objects to achieve the common business objectives. As knowledge,
methodologies and terminologies of the domains involved in the business case and represented through
those domains’ ontologies, but also individual contexts, abilities and capabilities are highly different,
they must be shared and adapted in advance or dynamically at runtime, enabling adequate cooperation
[5]
of actors and systems involved. Table 1 summarizes the different interoperability levels .
1) HL7 is a registered trademark of Health Level Seven International. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
2) openEHR is a registered trademark of the openEHR Foundation. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the product named.
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ISO 23903:2021(E)

Table 1 — Interoperability levels
Information Perspective Organization Perspective
Interoperability
Instances Interoperability Level
Level
Technical Technical plug&play, signal & protocol com- Light-weight interactions
patibility
Structural Simple EDI, envelopes Data sharing
Syntactic Messages and clinical documents with agreed Information sharing
vocabulary
Semantic Advanced messaging with common information Knowledge sharing at IT concept level in
models and terminologies computer-parsable form
Coordination
O rg a n iza t i o n / Common business process Knowledge sharing at business concept level
Service
Agreed service function level cooperation
Knowledge based Multi-domain processes Knowledge sharing at domain level
Cross-domain cooperation
Skills based Individual engagement in multiple domains Knowledge sharing in individual context
Moderated end-user collaboration
0.3  Motivation for the Interoperability and Integration Reference Architecture
Meeting the objectives of improving safety, quality and efficiency of care with ICT support requires
advancing interoperability between computer systems towards a business-process-specific co-
operation of actors representing the different domains participating in the business case. For that
purpose, the agreed domain knowledge, but also the individual and shared context (language, education,
skills, experiences, psychological, social, occupational, environmental aspects, etc.), need to be
represented correctly and formally for integration with the ICT system as part of the business system.
As the domain experts involved describe specific aspects of that business system in their own specific
contexts and using specific terminologies and ontologies, methodologies and frameworks, the resulting
informational representations are often quite inconsistent, requiring a peer-to-peer interoperability
adaptation process. Adapting existing standardized informational representations of domain-specific
use cases to changing contexts or contexts including multiple domains requires another common
harmonized informational representation, resulting in permanent revisions of specifications.
Modelling systems for multi-domain interoperability requires the advancement from the data model,
information model, and ICT domain knowledge perspective to the knowledge perspective of the
[6]
business domains . For achieving the latter, the relevant stakeholders are responsible to define the
provided view of the model as well as the way of structuring and naming the concepts of the problem
space. First capturing key concepts and key relations at a high level of abstraction, different abstraction
levels can be used iteratively. Thereby, the first iteration is performed in a top-down manner to
guarantee the conceptual integrity of the model. This demands meeting design principles such as
[7] [8]
orthogonality, generality, parsimony, and propriety. ISO 30401 defines the requirements for
knowledge management systems in organizations to meet business objectives.
It is impossible to represent the highly complex, highly dynamic, multi-disciplinary/multi-domain
healthcare system by one domain‘s terminology/ontology or – even worse for the reasons mentioned
right before - by exclusively using ICT ontologies and specific representation styles.
The alternative is an abstract domain-independent representation of systems using Universal Type
[9]
Theory and corresponding logics. The mathematical concept representation using a Meta Reference
[9]
Architecture according to the formal theory of the Barendregt Cube with Parameters in combination
with systems engineering methodologies allows representing any system architecturally (i.e. the
system’s components, their functions and internal as well as external relations) by generically describing
its composition/decomposition and behaviour from the perspectives of all domains of relevance in a
specific business case. A third dimension describes the system’s development process such as evolution
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ISO 23903:2021(E)

for living systems, manufacturing for technical systems, or a software development process, resulting
in a generic system model or Generic Reference Architecture presented in Figure 1. Details regarding
the dimensions of the model are explained in Clause 5 and Clause 6.
Figure 1 — Generic Reference Architecture model
To represent advanced interoperability and integration settings, different domain-specific
representations are linked to the same real world component. Therefore, an abstract and generic
reference architecture is needed which is able to represent any aspect or domain of interest. For
correctly and formally representing the concepts and relations of the domain-specific subsystems
involved in that business case, those subsystems are represented by their corresponding approved
domain ontologies, resulting in a system-theoretical, architecture-centric, top-level ontology driven
[10][11]
approach . Requirements for top level ontologies are specified in ISO 21838 (all parts). Health
3)
domain ontologies are SNOMED-CT® or specific ontologies such as the Open Biomedical Ontologies
[12] [13]
(OBO), including the Gene Ontology, maintained by the OBO Foundry .
As we can consistently model and compute only systems of reasonable complexity, the Generic Reference
Architecture model (Figure 1) can be used recursively at different granularity levels, so representing,
e.g. the continuum of real-world systems from elementary particles to the universe. The concepts of
the system’s components and their relations are represented in appropriate expressions in natural or
formal languages up to the basic level of primitives. The system analysis or design needs to address
partial systems when considering higher granularity levels of the system in question.
0.4  Technical approach
A system is a composition of interrelated components, ordered to accomplish a specific function or a
set of functions. Systems can be decomposed into subsystems or composed to form super-systems.
There are constructive or structural and behavioural or functional aspects of systems. According to
[14]
IEEE 1471, the architecture of a system is the fundamental organization of that system embodied in
its components, their relationships to each other and to the environment, and the principles guiding its
design and evolution. Rules for selecting and constraining components and functions as well as relations
according to a business case are called policies. Policies define the intended behaviour of a system. For
living systems, factors such as homeostasis, with the attributes of self-organization and self-regulation
as well as growth and development, reproduction, with the associated heredity (structure preservation)
and mutation (structural change), and higher development through selection of best-adapted variants
out of a large number make the description of living systems more complicated than that of technical
[15]
systems .
3) SNOMED CT is the registered trademark of the International Health Terminology Standards Development
Organisation (IHTSDO). This information is given for the convenience of users of this document and does not
constitute an endorsement by ISO of the product named.
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ISO 23903:2021(E)

In the 1970s and 1980s, a data level interoperability approach was developed by defining the
application and technology agnostic standard data exchange format EDI (electronic data interchange)
in order to transform proprietary data formats into the standard data format and vice versa.
[16]
Thus International Standards arose such as ISO 9735 (EDIFACT), or its healthcare-specific
[17]
pendant ISO/HL7 27931:2009, an application protocol for electronic data exchange in healthcare
environments. This document defines a generic system architecture for knowledge level interoperability.
It allows consistently transforming and interrelating any domain specific subsystem’s structure and
behaviour (e.g. domain specific standards and specifications) by ontologically representing its concepts
and relationships at the real world system component’s level of granularity in the abstract generic
component system. In other words, the domain specific subsystem (e.g. a domain specific standard or
specification) is re-engineered using the Interoperability and Integration Reference Architecture, by
that way providing a standardized interface to that specification. In this way, the methodology offered
in this document maps between domain specific or proprietary systems and their representation as
specification or domain specific standard by transforming them into a standard system architecture
and vice versa. Annex A demonstrates the integration of two domain specific standards by reengineering
[18]
the ISO 13606-1 Reference Model and the HL7® Composite Security and Privacy Domain Analysis
[19]
Model and combining them in an Interoperability and Integration Reference Architecture model
instance. Annex B demonstrates the integration of different communication standards by reengineering
4) 4)
HL7 v3® methodology and creating an adequate HL7 v2® methodology and transforming them into
an Interoperability and Integration Reference Architecture instance. In this way, the Interoperability
and Integration Reference Architecture supports the mutual transformation of those communications
standards for the sake of interoperability of existing solutions. For ontologically representing the
[20]
models, the Communication Standards Ontology (CSO) has been used. Figure 2 correspondingly
presents this standard’s interoperability approach. Annex C demonstrates the integration of different
[21]
standards in the light of ISO 12967(all parts) , while Annex D presents the approach in context of
5) [22]
ISO 13972 . Finally, Annex E demonstrates the deployment of this document’s Interoperability and
Integration Reference Architecture for the representation and harmonization of alternative reference
architectures.
4) HL7 v3 and HL7 v2 are registered trademarks of Health Level Seven International. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of the products named.
5) Under preparation. Stage at the time of publication: ISO/DIS 13972:2020.
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ISO 23903:2021(E)

Figure 2 — Overview of this document’s interoperability approach
Bound to the GCM Framework, inter-domain relationships need to happen at the same level of
[23]
granularity . To get there, intra-domain specializations/generalizations are performed.
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INTERNATIONAL STANDARD ISO 23903:2021(E)
Health informatics — Interoperability and integration
reference architecture – Model and framework
1 Scope
This document enables the advancement of interoperability from the data/information exchange
paradigm to knowledge sharing at decreasing level of abstraction, starting at IT concept level (semantic
coordination) through business domain concept level (agreed service function level cooperation),
domain level (cross-domain cooperation) up to individual context (skills-based end-user collaboration).
The document defines a model and framework for a harmonized representation of existing or intended
systems with a specific focus on ICT-supported business systems. The Interoperability and Integration
Reference Architecture supports ontology harmonization or knowledge harmonization to enable
interoperability between, and integration of, systems, standards and solutions at any level of complexity
without the demand for continuously adapting/revising those specifications. The approach can be
used for analysing, designing, integrating, and running any type of systems. For realizing advanced
interoperability, flexible, scalable, business-controlled, adaptive, knowledge-based, intelligent health
and social ecosystems need to follow a systems-oriented, architecture-centric, ontology-based and
policy-driven approach.
The languages for representing the different views on systems such as ontology languages like
[24] [25] [26]
Common Logic (CL) (ISO/IEC 24707 ) and Web Ontology Language (OWL) – specifically OWL 2
6)
(World Wide Web Consortium (W3C® ), languages for modeling and integrating business processes
7)
like Business Process Modeling Language (BPML) (OMG® ), but also OMG’s Unified Modeling
[27]
Language (UML, also specified as ISO/IEC 19505 ) based representation styles for the different
ISO/IEC 10746 (all parts) views are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10746 (all parts), Information technology — Open distributed processing — Reference model:
Architecture
ISO 22600 (all parts), Health informatics — Privilege management and access control
ISO/IEC 21838 (all parts), Information technology — Top-level ontologies (TLO)
OMG Ontology Definition Metamodel V1.1
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
6) W3C is a registered trademark of the World Wide Web Consortium. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
7) OMG is a registered trademark of The Object Management Group®. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of the products named.
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ISO 23903:2021(E)

— IEC Electropedia: available at http:// www .electropedia .org/
3.1
architecture
set of rules to define the structure of a system (3.25) and the interrelationships between its parts
[SOURCE: ISO/IEC 10746-2:2009, 6.6, modified — "(of a system)" removed from term.]
3.2
axiom
statement that is taken to be true, to serve as a premise for further reasoning
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.9, modified — Note to entry removed.]
3.3
business viewpoint
viewpoint (3.28) that is concerned with the purpose, scope and policies governing the activities of the
specified ecosystem (3.10)
3.4
class
type
general entity (3.11)
8)
[SOURCE: ISO/IEC/PRF 21838-1:— , 3.2, modified — “type” added as second preferred term, note to
entry removed.]
3.5
collection
group of particulars (3.19)
9)
[SOURCE: ISO/IEC/PRF 21838-2:— , 3.4, modified — Notes to entry removed.]
3.6
concept
unit of knowledge created by a unique combination of characteristics
Note 1 to entry: Concepts are not necessarily bound to particular natural languages. They are, however,
influenced by the social or cultural background which often leads to different categorizations.
Note 2 to entry: As a knowledge component, a concept can be specialized and generalized as components can.
[SOURCE: ISO 1087:2019, 3.2.7, modified — Note 2 to entry replaced.]
3.7
definition
representation of a concept by a descriptive statement which serves to differentiate it from related
concepts
[SOURCE: ISO 1087:2019, 3.3.1]
3.8
domain
collection (3.5) of entities (3.11) of interest to a certain community or discipline
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.17, modified — Example and note to entry removed.]
8) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-1:2020.
9) Under preparation. Stage at the time of publication: ISO/IEC/PRF 21838-2.2:2020.
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ISO 23903:2021(E)

3.9
domain ontology
ontology (3.18) whose terms (3.26) represent classes or types (3.4) and, optionally, certain particulars
(3.19) (called ‘distinguished individuals’) in some domain (3.8)
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.18]
3.10
ecosystem
structured systems (3.25) and communities that are governed by general rules
3.11
entity
object
item that is perceivable or conceivable
Note 1 to entry: The terms ‘entity’ and ‘object’ are catch-all terms analogous to ‘something’. In terminology
circles ‘object’ is commonly used in this way. In ontology circles, ‘entity’ and ‘thing’ are commonly used.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.1]
3.12
expression
word or group of words or corresponding symbols that can be used in making an assertion
Note 1 to entry: Expressions are divided into natural language expressions and expressions in a formal language.
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.5]
3.13
formal language
language that is machine readable and has well-defined semantics
[SOURCE: ISO/IEC/PRF 21838-1:—, 3.10, modified — Note removed.]
3.14
formal theory
collection (3.5) of definitions (3.7) and axioms (3.2) expressed in a formal language (3.13)
[SOURCE: ISO/IEC/PRF 21838-1: —, 3.11, modified — Note removed.]
3.15
instance
particular (3.19) that instantiates some universal (3.27)
[SOURCE: ISO/IEC/PRF 21838-2:—, 3.6, modified — Example removed.]
3.16
interoperability
ability of a system (3.25) or a product to work with other systems (3.25) or products without special
effort on the part of the customer
Note 1 to entry: Under traditional ICT focus, interoperability is ability of two or more systems or components to
[29]
exchange information and to use the information that has been exchanged .
[SOURCE: IEEE Standards Glossary]
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