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Release: 24.03 (current)

CX-0004 Governance Process for Aspect models v1.0.1

ABSTRACT​

This standard describes the governance process that shall be followed to create, update or deprecate an aspect model. This process is the prerequisite for any model submitted as a standardization candidate in Catena-X.

1. Introduction​

1.1 Audience & Scope​

This section is non-normative

This standard is relevant for

  • Business Application Provider
  • Data Provider / Consumer
  • Core Service Provider
  • Enablement Service Provider
  • Consulting Service Provider

Some additional notes for stakeholders affected from governance of semantic models:

  • Business application providers or business owners who are in need of new data that shall be exchanged and thus need new or updated aspect models need to be aware of the governance process of semantic models
  • Business owners who want to deprecate an existing aspect model need to be aware of the governance process of semantic models
  • Technical Committee for Standardization of Catena-X: only models that were created and maintained following the governance process as defined in this standard are allowed to be submitted as standardization candidates

1.2 Context​

This section is non-normative

Catena-X standardized semantic models are an important enabler for interoperability. Only when partners and business apps speak the "same language", can data be exchanged seamlessly between use-cases and apps. A semantic model that is standardized within Catena-X is needed when:

  • The consumer of the data isn't known prior to the data exchange
  • Multiple consumers want to use the data
  • The data is processed by various business apps in multiple use-cases

The semantic models are included in the Semantic Hub. The Semantic hub provides a UI and search possibilities.

1.3 Conformance​

As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.

The key words MAY, MUST, MUST NOT, OPTIONAL, RECOMMENDED, REQUIRED, SHOULD and SHOULD NOT in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

1.4 Proof of conformity​

This section is non-normative

All participants and their solutions will need to prove that they conform to the Catena-X standards. To validate that the standards are applied correctly, Catena-X employs Conformity Assessment Bodies (CAB).

The resulting aspect models of modelling activities MUST be element of

https://github.com/eclipse-tractusx/sldt-semantic-models with status "Released". It MUST be ensured that all modelling stages were successful. The modelling stages are ensured by github actions and corresponding checklists (see also public documentation in github: https://github.com/eclipse-tractusx/sldt-semantic-models/blob/main/documentation/GOVERNANCE.md)

1.5 Terminology​

This section is non-normative

Aspect

a domain-specific view on information and functionality associated with a specific Digital Twin with a reference to a concrete Aspect Model.

Note 1 to entry: An Aspect is a software service to retrieve the actual runtime data of a Digital Twin (current or aggregated) from a data source or to trigger operations. Thus, an aspect is built with an implementation that ensures that the exchanged data is compliant to the specification of the referenced Aspect Model via a defined interface.

Note 2 to entry: Aspects are registered (incl. their "API endpoint" information) with the Digital Twin to which they belong in the Digital Twin Registry.

Note 3 to entry: an aspect corresponds to a Submodel in the Asset Administration Shell

Aspect Model

a formal, machine-readable semantic description (expressed with RDF/turtle) of data accessible from an Aspect.

Note 1 to entry: An Aspect Model must adhere to the Semantic Aspect Meta Model (SAMM), i.e., it utilizes elements and relations defined in the Semantic Aspect Meta Model and is compliant with the validity rules defined by the Semantic Aspect Meta Model.

Note 2 to entry: Aspect models are logical data models which can be used to detail a conceptual model in order to describe the semantics of runtime data related to a concept. Further, elements of an Aspect model can/should refer to terms of a standardized Business Glossary (if existing)​.

Note 3 to entry: An Aspect Model describes the semantics of a Submodel. A Submodel Template guides the creation of a Submodel conformant to the Aspect Model and the Asset Administration Shell.

Asset Administration Shell

standardized digital representation of an asset

Note 1 to entry: Asset Administration Shell and Administration Shell are used synonymously.

[SOURCE: IEC 63278-1, note added]

Digital Twin

digital representation, sufficient to meet the requirements of a set of use cases

Note 1 to entry: in this context, the entity in the definition of digital representation is typically an asset.

[SOURCE: IIC Vocabulary IIC:IIVOC:V2.3:20201025, adapted (an asset, process, or system was changed to an asset)]

digital representation

information and services representing an entity from a given viewpoint

EXAMPLE 1: examples of information are properties (e.g., maximum temperature), actual parameters (e.g., actual velocity), events (e.g., notification of status change), schematics (electrical), and visualization information (2D and 3D drawings).

EXAMPLE 2: examples of services are providing the history of the configuration data, providing the actual velocity, and providing a simulation.

EXAMPLE 3: examples of viewpoints are mechanical, electrical, or commercial characteristics.

[SOURCE: IEC 63278-1, editorial changes]

2. Governance Process for Aspect Models​

The governance process including its three modelling stages as described in

https://github.com/eclipse-tractusx/sldt-semantic-models/blob/main/documentation/GOVERNANCE.md MUST be followed. The process includes guidance for new models, for updating existing models and for deprecating existing semantic models.

The Quality Gates for these three modelling stages are as follows:

MS1_Approved, Checklist "MS1 Request for Model Development" is approved.

MS2_Approved, Checklist "MS2 Valid Model" is approved.

MS3_Approved, Checklist "MS3 Release Model" is approved. The associated pull request can be merged to the "main-branch".

These Quality Gates MUST be fulfilled for the different modelling stages of an aspect model. This includes conformance to CX-0003.

Every aspect model MUST have a unique identifier. This identifier MUST be used for registering an aspect/a submodel in the digital twin/the Asset Administration Shell of a specific asset. For more details see standards CX-0003 and CX-0002.

3. References​

3.1 Normative References​

  • CX-0002 DIGITAL TWINS IN CATENA-X
  • CX-0003 SAMM SEMANTIC ASPECT META MODEL

3.2 Reference Implementations​

This section is non-normative

The process is implemented in https://github.com/eclipse-tractusx/sldt-semantic-models

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