Fact Sheet: ISO 10303-242 (STEP AP242)

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Short description/
Transmitted information
  • 3D model-based engineering information
  • product data including product and document structure, change and configuration management
  • 3D CAD models (geometry, topology, PMI) and visualization
  • Validation properties
  • Kinematics
  • Composites
Normative document ISO 10303-242:2020
Release status
Edition 2
Release date April 2020
Application scope
  • Data exchange
  • Data sharing and collaboration
  • Engineering backbone
  • Reference model
  • Long term archiving
  • Coverage of the most of the many different automotive and aerospace use cases in product development with a common format
  • Interoperability between CAx systems and PLM systems
  • Provide a reference model for engineering data
  • Provide a common engineering backbone with links to various other standards and domain specific specifications
Promoting bodies
IT standard classification
  • Interoperability standard
  • Process standard
  • Integration standard
Data format(s)
  • Text format (ASCII)
  • Encoded in EXPRESS or XML
Additional available resources
  • Recommended practices (implementation guidelines)
  • Benchmarks
  • Benchmark short reports
  • Benchmark long reports
  • Test suite documents
  • Testing files
  • Use cases
  • Guidelines
  • Best practice
  • Best practices examples
  • Round table presentations
Relevant prostep ivip project groups

Positioning of ISO 10303-242 in V-Model

The Fact Sheet basically covers the entire scope of the standard. However, prostep ivip respectively SSB recommends AP 242 only for a restricted scope and for some areas such as requirements and electrical harnesses alternatives such as ReqIF and KBL/VEC


STEP AP242 is the successor of AP203 and AP214.

STEP AP 242 Edition 1 (published in 2014) provides all the functionalities covered by the AP 203 ed2 and AP 214 ed3.  It includes also new functionalities, such as:

  • The “Shape Quality” modules, derived from STEP Part 59 and based on the SASIG PDQ guidelines,
  • The results of the PDM harmonization between STEP AP 242 Business Object Model, now called Domain Model, and AP 239 PLCS Platform Specific Model,
  • A new model for  STEP 3D tessellated geometry and
  • New generic capabilities for STEP “external element references” used for kinematics and other disciplines.

AP 242 Edition 2 (published in 2020) is the extension of AP 242 Edition 1 to the electrical design domain, completed with specific enhancements in the following domains:

  • PDM,
  • 3D geometry,
  • 3D PMI,
  • Composites and
  • Mechanical design

AP 242 Edition 3 is a corrective maintenance edition.

AP 242 Edition 4 is in development. prostep ivip and VDA are proposing the following extensions:

  • Assembly PMI
  • Visual issue management
  • Improvement of the external element reference mechanism

Further extensions for Edition 3 are planned by other stakeholders.

STEP AP 242 has 2 coordinated and closely interlinked information models each with its own implementation form:

  • AIM model for Part 21 (ASCII) file exchange
  • Domain Model for XML file exchange

The Domain Model scope is a subset of the AIM model scope. The focus of the Domain Model is on product structure data incl. metadata providing the basis for the engineering backbone.

PMI currently only present in the AIM Model is planned to be added ito the Domain Model in Edition 4.

Relevance and Benefit for MBSE

The benefits of using STEP AP242 are

  • Combination of AP242 and other protocols (e.g. 243) provides added value
  • Established standard for PDM (product structure, configurations)
  • Backbone to which other standards may be docked