ISO 20022-5:2013

INTERNATIONAL ISO
STANDARD 20022-5
First edition
2013-05-01

Financial services — Universal financial
industry message scheme —
Part 5:
Reverse engineering
Services financiers — Schéma universel de messages pour l'industrie
financière —
Partie 5: Ingénierie inverse




Reference number
ISO 20022-5:2013(E)
©
ISO 2013

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ISO 20022-5:2013(E)

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ISO 20022-5:2013(E)
Contents Page
Foreword . iv
Introduction . vi
1  Scope . 1
2  Normative references . 2
3  Terms and definitions . 2
4  Activities and deliverables . 3
4.1  General . 3
4.2  Gap analysis . 3
4.3  Development of ISO 20022 compliant BusinessTransactions and MessageSets . 4
4.4  ISO 20022 Registration . 4
4.5  Preparation of migration . 4
5  Workflow . 5
5.1  General . 5
5.2  Gap analysis . 5
5.2.1  General . 5
5.2.2  IndustryMessageSet documentation collection . 6
5.2.3  BusinessArea gap analysis . 8
5.2.4  BusinessProcess gap analysis . 9
5.2.5  BusinessTransaction gap analysis . 11
5.2.6  MessageDefinition gap analysis . 14
5.2.7  BusinessRoles gap analysis . 17
5.3  Development of ISO 20022 compliant BusinessTransactions and MessageSets . 19
5.3.1  General . 19
5.3.2  A new BusinessArea . 20
5.3.3  A modified BusinessArea . 21
5.3.4  A new BusinessProcess . 21
5.3.5  A modified BusinessProcess . 22
5.3.6  A requirements use case . 22
5.3.7  A new BusinessTransaction . 23
5.3.8  A modified BusinessTransaction . 23
5.3.9  A new MessageDefinition . 24
5.3.10  A modified MessageDefinition . 25
5.3.11  A new or modified BusinessRole . 25
5.4  ISO 20022 registration . 26
5.5  Preparation of migration . 26
5.5.1  General . 26
5.5.2  Convergence documentation . 26
5.5.3  Coexistence documentation . 30
5.5.4  Migration planning . 30
Annex A (informative) Convergence documentation . 32
Bibliography . 36

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ISO 20022-5:2013(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 20022-5 was prepared by Technical Committee ISO/TC 68, Financial services.
This first edition cancels and replaces ISO/TS 20022-5:2004.
ISO 20022 consists of the following parts, under the general title Financial services — Universal financial
industry message scheme:
 Part 1: Metamodel
 Part 2: UML profile
 Part 3: Modelling
 Part 4: XML Schema generation
 Part 5: Reverse engineering
 Part 6: Message transport characteristics
 Part 7: Registration
 Part 8: ASN.1 generation
ISO 20022-1:2013, ISO 20022-2:2013, ISO 20022-3:2013, ISO 20022-4:2013, ISO 20022-5:2013,
ISO 20022-6:2013, ISO 20022-7:2013 and ISO 20022-8:2013 will be implemented by the Registration
Authority by no later than the end of May 2013, at which time support for the concepts set out within them will
be effective. Users and potential users of the ISO 20022 series are encouraged to familiarize themselves with
the 2013 editions as soon as possible, in order to understand their impact and take advantage of their content
as soon as they are implemented by the Registration Authority. For further guidance, please contact the
Registration Authority.
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ISO 20022-5:2013(E)
For the purposes of research on financial industry message standards, users are encouraged to
share their views on ISO 20022:2013 and their priorities for changes to future editions of the
document. Click on the link below to take part in the online survey:
http://www.surveymonkey.com/s/20022_2013

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ISO 20022-5:2013(E)
Introduction
This International Standard defines a scalable, methodical process to ensure consistent descriptions of
messages throughout the financial services industry.
The purpose of this International Standard is to describe precisely and completely the externally observable
aspects of financial services messaging in a way that can be verified independently against operational
messaging.
The trigger for the creation of this International Standard was the rapid growth in the scale and sophistication
of messaging within financial services during the 1990s using ISO 15022. The financial services industry (from
here on referred to as "the industry") created the first version of this International Standard as the successor to
ISO 15022 in response to that trigger. Since ISO 15022, the industry has broadened the scope from securities
to the entire industry for this International Standard.
This International Standard is based on open technology standards, which historically have evolved more
rapidly than the industry itself. Consequently, this International Standard adopted a model-driven approach
where the model of the industry's messaging can evolve separately from the evolution of the messaging
technology standards. The period during which this International Standard has emerged followed the
widespread adoption of the World Wide Web (the Web) for business. XML (eXtensible Mark-up Language)
emerged as the de facto standard for document representation on the Web and it became the first syntax for
ISO 20022.
The modelling process is further refined into three levels which, in addition to the messaging technology
standard, is why this International Standard is based on four levels: the Scope level, the Conceptual level, the
Logical level and the Physical level.
This four-level approach is based on the first four levels of the Zachman Framework. The remaining two levels
of the Zachman Framework are equivalent to the implementations and the operational levels, respectively.
In ISO 20022-1, the first, second and third levels are described in UML (Unified Modelling Language) because
it is widely supported and supports multiple levels of abstraction. The models created in accordance with this
International Standard are technology independent in that they do not require any particular physical
expression or implementation. Such models aim to describe all parts of the message exchange. The models
form the definition of the protocol between participants exchanging messages. This International Standard
defines a method that describes a process by which these models can be created and maintained by the
modellers.
The models and the Physical level artefacts are stored in a central repository, serviced by a Registration
Authority. This International Standard's repository is available on the World Wide Web and offers public
access for browsing.
The Repository is organized into two areas:
 A DataDictionary containing the industry model elements likely to have further or repeated use.
 A BusinessProcessCatalogue that contains models describing specific message definitions and business
processes, and physical syntax implementations.
This International Standard is organized into the following parts.
 ISO 20022-1 describes in MOF (Meta-Object Facility) the metamodel of all the models and the Repository.
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ISO 20022-5:2013(E)
 ISO 20022-2 covers the UML profile, a grounding of general UML into a specific subset defined for this
International Standard (to be used when UML is selected to define the models).
 ISO 20022-3 describes a modelling method to produce models for this International Standard.
 ISO 20022-4 covers XML schema generation rules to transform a Logical level model into a Physical level
description in the syntaxes.
 This part of ISO 20022 covers logical model alignment and reverse engineering of existing message
syntaxes.
 ISO 20022-6 covers message transport characteristics that define the quality of service required by the
business process definitions so that they can operate successfully.
 ISO 20022-7 describes the process of managing the registration of models and physical syntax
implementations.
 ISO 20022-8 gives ASN.1 syntax generation rules to transform a Logical level model into a Physical level
description in ASN.1.

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INTERNATIONAL STANDARD ISO 20022-5:2013(E)

Financial services — Universal financial industry message
scheme —
Part 5:
Reverse engineering
1 Scope
This part of ISO 20022 was prepared to complement ISO 20022-1. The reverse engineering guidelines
explain how to extract relevant information from existing IndustryMessageSets in order to prepare the
submission to the ISO 20022 Registration Authority of equivalent, ISO 20022 compliant BusinessTransactions
and MessageSets.
The ISO 20022 Repository will contain all ISO 20022 compliant BusinessTransactions and MessageSets, as
outlined in ISO 20022-1. The approach to be followed for adding ISO 20022 compliant BusinessTransactions
and MessageSets to the Repository can be classified according to the following scenarios.
a) Case 1:
 No ISO 20022 compliant BusinessTransactions and MessageSets exist.
 No IndustryMessageSet exists.
EXAMPLE Collective Investment Vehicles.
 Approach: full development of ISO 20022 compliant BusinessTransactions and MessageSets using ISO
20022-3.
b) Case 2:
 No ISO 20022 compliant BusinessTransactions and MessageSets exist.
 One or more IndustryMessagesets exist.
EXAMPLE Securities Pre-Trade (FIX MessageSet exists).
 Approach: conversion of the IndustryMessageSet(s) into ISO 20022 compliant BusinessTransactions and
MessageSets, using ISO 20022-5.
c) Case 3:
 ISO 20022 compliant BusinessTransactions and MessageSets exist.
 One or more existing IndustryMessageSets exist as well.
EXAMPLE Securities Post-Trade (FIX, Omgeo MessageSets exist).
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ISO 20022-5:2013(E)
 Approach: comparison of the existing IndustryMessageSet(s) with the ISO 20022 compliant
BusinessTransactions and MessageSets and extension of the ISO 20022 compliant
BusinessTransactions and MessageSets as necessary, using ISO 20022-5.
This part of ISO 20022 describes the activities of ISO 20022 reverse engineering from the point of view of the
user who wants to verify that the business functionality, covered by his own IndustryMessageSet, is covered
by ISO 20022 compliant BusinessTransactions and MessageSets. The intention of this part of ISO 20022 is
not to attempt to define a “methodology” for reverse engineering.
It describes the following set of required activities.
1) Extract relevant information from existing IndustryMessageSets and compare it to the related
information in the ISO 20022 Repository.
2) Use the results of this comparison for the development of ISO 20022 compliant
BusinessTransactions and MessageSets.
3) Submit the resulting update requests to the Registration Authority.
NOTE It is not the intention of reverse engineering to systematically create ISO 20022 compliant versions of all
existing IndustryMessageSets. Update requests are always based on a valid business justification.
4) Prepare the migration to the ISO 20022 compliant BusinessTransactions and MessageSets.
The main objectives of this part of ISO 20022 are to:
 capture the industry knowledge covered by existing IndustryMessageSets;
 build upon former standardization efforts in the industry when building ISO 20022 compliant
BusinessTransactions and MessageSets;
 ensure that the resulting ISO 20022 compliant BusinessTransactions and MessageSets cover fully the
business scope of existing IndustryMessageSets;
 maximize interoperability between existing IndustryMessageSets and ISO 20022 compliant
BusinessTransactions and MessageSets;
 support the migration from existing IndustryMessageSets to ISO 20022 compliant BusinessTransactions
and MessageSets.
2 Normative references
The following referenced documents are indispensable for the application 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 20022-1, Financial services — Universal financial industry message scheme — Part 1: Metamodel
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 20022-1 and the following apply.
3.1
IndustryMessage
message that offers a particular MessageDefinition functionality (possibly multi-functional) and whose
MessageDefinition is part of an IndustryMessageSet
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ISO 20022-5:2013(E)
3.2
message item
element or field used at a particular place in a MessageDefinition
NOTE This exact place is typically described by the MessagePath.
3.3
MessagePath
exact position in a particular MessageDefinition
NOTE This position is uniquely identified by the full hierarchy (i.e. “path”) from the message level (i.e. the highest
level) down to the element level (i.e. the lowest level).
4 Activities and deliverables
4.1 General
There are four main activities in the ISO 20022 reverse engineering:
— gap analysis;
— development of ISO 20022 compliant BusinessTransactions and MessageSets;
— ISO 20022 registration;
— preparation of migration.
The major objectives and deliverables related to these activities are described in this clause.
4.2 Gap analysis
The objectives of the gap analysis are to:
a) determine the BusinessArea of the IndustryMessageSet and identify the corresponding BusinessArea,
BusinessProcesses, activities and supporting BusinessTransactions in the ISO 20022 BusinessProcess
Catalogue;
b) compare Business Participants in ISO 20022 BusinessProcesses and BusinessTransactions to the
parties that use the IndustryMessages, or that are identified in the IndustryMessages;
c) verify whether existing MessageInstances offer the complete MessageDefinition functionality that is
offered by the IndustryMessages;
d) evaluate whether the business content of the relevant MessageInstances cover the business content of
the individual IndustryMessages;
e) compare the meaning and the data typing of the used MessageComponentTypes and/or
BusinessComponents to the individual IndustryMessage items.
The deliverables of the gap analysis are as follows.
1) Documentation concerning the coverage, the differences and the gaps between the
IndustryMessageSet and the ISO 20022 compliant BusinessTransactions and MessageSets. This
documentation concerns the following repository items:
 BusinessAreas;
 BusinessProcesses;
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ISO 20022-5:2013(E)
 BusinessTransactions and MessageSets;
 MessageDefinitions (including MessageDefinition Constraints);
 BusinessRoles;
 BusinessComponents (including BusinessElements and Constraints);
 MessageComponentTypes (including MessageElements and Constraints);
 DataTypes.
2) The documentation of the IndustryMessageSet for those repository items that were missing (i.e.
the gaps) or for which a difference was identified.
4.3 Development of ISO 20022 compliant BusinessTransactions and MessageSets
The objectives of this activity are to:
 complete the gap analysis with all additional information that is required to define or complete ISO 20022
compliant BusinessTransactions and MessageSets;
 define the required updates and additions to the existing ISO 20022 compliant BusinessTransactions and
MessageSets.
This step shall focus only on the identified gaps and differences. It shall verify whether a valid business
justification exists to include this additional information to rectify these gaps and differences in the ISO 20022
repository. It shall also take into account that the goal of reverse engineering is not to question (except with
respect to business justification), modify or complement the business functionality that is currently supported
in the IndustryMessageSet.
The deliverable of this activity is a detailed documentation describing how the existing ISO 20022 compliant
BusinessTransactions and MessageSets shall be updated to incorporate the identified gaps and differences.

4.4 ISO 20022 Registration
The objective of this activity is to prepare the information in order for the ISO 20022 Registration Authority to
request the update of the ISO 20022 repository with all required additions and modifications.
The deliverables are the requests to the ISO 20022 Registration Authority to add or modify Dictionary Items
and/or Catalogue Items.
4.5 Preparation of migration
The objectives of this activity are as follows.
a) To define and document the relationship between the IndustryMessageSet and ISO 20022 compliant
BusinessTransactions and MessageSets. The required amount of information will depend on the chosen
migration path:
— in case of a “big bang” migration, it will be sufficient to only document the relationship in a way
that supports the convergence towards ISO 20022;
— in case of an accepted period of coexistence, there will be a need to have “bi-directional”
documentation that not only supports the convergence towards ISO 20022, but also a
backwards mapping to the IndustryMessageSets.
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ISO 20022-5:2013(E)
b) To define a plan for the migration to the ISO 20022 compliant BusinessTransactions and MessageSets.
The deliverables of this activity are:
1) the convergence documentation,
2) the coexistence documentation (optional), and
3) the migration plan.
5 Workflow
5.1 General
This clause contains a detailed workflow description of the four main activities in ISO 20022 reverse
engineering.
5.2 Gap analysis
5.2.1 General
5.2.1.1 Preliminary remarks
The gap analysis requires considerable expertise and documentation regarding the IndustryMessageSet. In
case this documentation is not readily available, it will be necessary to perform a thorough analysis of the
IndustryMessageSet and its use (see the first step in Figure 1).
The gap analysis also requires considerable documentation about the ISO 20022 compliant
BusinessTransactions and MessageSets. The repository outputs will include this documentation.
Gap analysis is crucial for all subsequent steps.
— Identifying the differences and gaps will define the scope of the subsequent development of
ISO 20022 compliant BusinessTransactions and MessageSets and ISO 20022 registration.
— Identifying the overlaps will provide the required information for the convergence
documentation and the related migration.

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ISO 20022-5:2013(E)
5.2.1.2 Main steps
The main steps in gap analysis are shown in the following diagram.


IndustryMessageSet documentation

collection

Business Area gap analysis

Business Process gap analysis

Business Transaction gap analysis

Message Definition gap analysis

Business Roles gap analysis

Figure 1 — Main steps in gap analysis
These steps, which are described in more detail in subsequent clauses, will be executed in an iterative and
incremental way. In the “reverse engineering case 2” scenario (i.e. no existing ISO 20022 compliant
BusinessTransactions and MessageSets, as described in the Scope) it is necessary to collect only the
IndustryMessageSet documentation.
5.2.2 IndustryMessageSet documentation collection
If the IndustryMessageSet is well documented (i.e. a full description including the BusinessArea, the
BusinessProcesses and the BusinessTransactions), this step is limited to the explicit identification of the
documentation set.
In many cases, however, the IndustryMessageSet documentation focuses only on the MessageDefinitions
and mainly documents the functionality and content of all IndustryMessages. In some cases, even this
documentation might be very limited (e.g. restricted to a description of the physical structure). In these cases,
it is mandatory to complete the IndustryMessageSet documentation prior to the reverse engineering.
The recommended approach to complete the IndustryMessageSet documentation is depicted in the following
diagram and further explained in the text.
1) Start from the description of the IndustryMessage.
2) For each IndustryMessage, describe the MessageDefinition functionality (i.e. the purpose or
purposes for which the IndustryMessage can be used). Note that IndustryMessages can be multi-
functional and that each function should be described.
3) Describe for each IndustryMessage item the business meaning. The meaning of the Item might
depend on the specific MessageDefinition functionality, in case the IndustryMessage is multi-
functional. In this case, all meanings shall be described.

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ISO 20022-5:2013(E)
Industry Message description

MessageDefinition functionality

Describe business meaning

Extract BusinessRoles

Identify BusinessTransactions

Identify BusinessProcesses

Identify BusinessAreas


Figure 2 — Recommended approach to complete the IndustryMessageSet documentation
NOTE 1 One of the big challenges of this step is to identify the real business meaning of the fields, e.g. one
IndustryMessage field might contain multiple BusinessElements and might contain partial BusinessElements. In such
cases, it might have to be combined with other IndustryMessage fields to obtain meaningful BusinessElements.
NOTE 2 A multi-functional IndustryMessage will also contain fields to specify the used functionality. These fields do not
have a corresponding MessageElement in the MessageInstance. For these fields, document the MessageDefinition
functionality they represent.
NOTE 3 An IndustryMessage might contain “technical” fields, which have no business meaning. In some cases, these
fields might have a corresponding technical MessageElement in the ISO 20022 MessageDefinition but they will never
have a corresponding BusinessElement.
4) Extract from each IndustryMessage the BusinessRoles. This is done by identifying the functional
roles of the sender and the receiver of the IndustryMessage and by identifying the functional roles of
all other parties that appear in the IndustryMessage content.
NOTE 4 “BusinessRoles” indicate functional roles (e.g. buyer, seller, etc.).
5) Analyse the use of the IndustryMessages in order to identify the “BusinessTransactions” (i.e. the
different message flows that occur in the industry) in which the IndustryMessages are used.
Document each of these BusinessTransactions, ideally using a message flow diagram and a textual
description.
6) Analyse the list of identified BusinessTransactions in order to identify the BusinessProcesses that are
supported.
7) Identify the BusinessArea(s) to which the BusinessProcesses belong.

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ISO 20022-5:2013(E)
5.2.3 BusinessArea gap analysis
5.2.3.1 General
The objective o
...