ISO/TS 10303-16:2021

TECHNICAL ISO/TS
SPECIFICATION 10303-16
First edition
2021-07
Industrial automation systems
and integration — Product data
representation and exchange —
Part 16:
Description methods: SysML XMI to
EXPRESS transformation
Reference number
©
ISO 2021
© ISO 2021
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ii © ISO 2021 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 2
3.1 Terms and definitions . 2
3.1.1 Terms and definitions for generic concepts . 2
3.1.2 Terms and definitions for SysML constructs . 3
3.2 Abbreviated terms . 5
4 SysML XMI to EXPRESS. 5
4.1 General . 5
4.2 Presentation conventions . 5
4.3 Common mapping conventions . 5
4.3.1 Reference to external files . 5
4.3.2 xmi:id, xmi: uuid, and UUID . 6
4.3.3 Assumed sysml:Blo ck in fragments . 6
4.3.4 Containment and reference relationship . 6
4.3.5 Used stereotypes to represent STEP concepts . 6
4.3.6 Select type not treated as SysML supertype. 7
4.4 Mapping of the primary schema . 7
4.5 Mapping of Entities . 7
4.5.1 General mapping of Entity . 7
4.5.2 Mapping of abstract entity . 7
4.5.3 Mapping of entity with one supertype . 8
4.5.4 Mapping of entity with multiple supertypes . 8
4.6 Mapping of simple type . 9
4.7 Mapping of aggregation type .11
4.8 Mapping of aggregation of aggregation type.12
4.9 Mapping of Select type .13
4.9.1 General mapping of select type .13
4.9.2 Mapping of select type containing value type .14
4.10 Mapping of enumeration type .15
4.11 Mapping of entity attribute .15
4.11.1 Mapping of multiplicity and optionality .16
4.11.2 Attribute typed as an Entity .18
4.11.3 Attribute typed as Select .18
4.11.4 Attribute typed as Enumeration type .19
Annex A (normative) Information object registration .20
Annex B (informative) EXPRESS/Information modelling constructs and the equivalent
SysML modelling constructs .21
Bibliography .33
Foreword
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electrotechnical standardization.
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editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 184, Automation systems and integration,
Subcommittee SC 4, Industrial data.
A list of all parts in the ISO 10303 series can be found on the ISO website.
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

Introduction
ISO 10303 is an International Standard for the computer-interpretable representation and exchange
of product data. The objective is to provide a neutral mechanism capable of describing product data
throughout the life cycle of a product and independent from any particular system. The nature of this
description makes it suitable not only for neutral file exchange, but also as a basis for implementing and
sharing product databases and archiving.
10303-16 is a member of the description methods series. This document specifies a mapping of SysML
XMI to the EXPRESS language.
The STEP APs Domain models and the STEP Core Model are information model layer components that
are part of the STEP Extended Architecture. These components are developed using SysML. In the past
STEP information models were developed using the EXPRESS language. For legacy reasons it is therefore
required to provide an EXPRESS schema derived from the SysML domain model. It is mandatory that
the transformation from the SysML model to the EXPRESS schema is defined by a reference standard
and guarantee a repeatable process applicable to future application protocols developments.
The Object Management Group (OMG) has standardized the XML Metadata Interchange specification
(XMI) that integrates the OMG Systems Modeling Language (SysML), the OMG Unified Modeling
Language (UML), the OMG Meta-Object Facility (MOF) and the World Wide Web Consortium (W3C)
Extensible Markup Language (XML) standards. SysML inherits the XMI interchange capability from
UML. XMI is a mechanism for the interchange of metadata between UML-based modeling tools and MOF-
based metadata repositories. OMG has also standardized an XMI compliant interchange format for the
SysML thus specifying a lexical representation of SysML models based on a standardized metamodel
of the SysML. That lexical representation includes, among other things, the ability to interchange data
type information, class information (or entities), groupings of classes providing namespaces for the
classes (or schemas), associations between classes and inheritance between classes (or subtypes).
ISO has standardized the EXPRESS language (ISO 10303-11:2004). It is used to specify information
requirements in ISO 10303.
10303-16 specifies a description method of the STEP Parts family, which defines the transformation of
SysML constructs to the EXPRESS elements. Because the XMI standard specifies the XML representation
of SysML metamodel constructs, standardizing the binding of SysML constructs into EXPRESS elements
supports the representation of SysML models as EXPRESS schemas. SysML metamodel concepts that
appear in SysML Block Diagrams are mapped into data specifications defined by EXPRESS schemas.
This document does not map all SysML metamodel constructs to EXPRESS elements, because 10303
SysML models do not use all SysML metamodel constructs.
The EXPRESS schemas are derived from the domain model by applying the implementation bindings
on the SysML XMI. The EXPRESS binding is realized with XSL transformations, which transforms the
SysML model into an EXPRESS Schema. The specified binding is a one-way transformation from SysML
information model represented in XMI into an EXPRESS schema. Due to this limitation 10303-16 does
not define the transformation of arbitrary SysML models to EXPRESS.
Readers of 10303-16 require detailed knowledge of the EXPRESS language, and SysML.
The structure, conventions and concepts of the EXPRESS language are defined in ISO 10303-11:2004.
The main component of this standard is:
— the specification of the transformation from SysML XMI to EXPRESS for each STEP element modelled
in SysML.
TECHNICAL SPECIFICATION ISO/TS 10303-16:2021(E)
Industrial automation systems and integration — Product
data representation and exchange —
Part 16:
Description methods: SysML XMI to EXPRESS
transformation
1 Scope
This document specifies a mapping of SysML (ISO/IEC 19514:2017) constructs t
...