AP 242 Edition 2 has enhanced functionalities for Electrical Harness interoperability

The objective of this page is to provide an overview of the enhanced functionalities of STEP AP242 edition 2 (International Standard in April 2020) for Electrical Wiring Harness interoperability. It is summed up according to the following paragraphs:

  • Overview and illustration of capabilities
  • Examples of associated use cases
  • Examples of associated test cases
  • Dependencies / related standards
  • Status of development
  • Status of prototyping in COTS solutions
  • Related Interoperability Forum: EWIS-IF
  • Planned extensions for Electrical domain in STEP AP242 Edition 3

Overview and illustration of capabilities

The European industries have developed between 1995 and 2000, the standard STEP AP 212 “Electrotechnical design and installation”. Despite some successful implementations in certain domains, this standard was not maintained, judged as relying on too much generic information, complex to be implemented. As a result, there is no ISO standard used as the reference for interoperability of wiring and electrical harness design information. STEP AP 242 ed2 aims to close this gap.

The proposed extensions of STEP AP 242 ed2 to Electrical wiring and harness design cover the following functionalities (see White Paper for more details):

  •  Physical electrical harness model for design and construction,
  •  Electrical functional connectivity information.

It covers the information needed for the design and manufacturing of the harness (harness topology, connectors, terminals, contacts, wires, cables, protections, backshells, supports…)

It is fully integrated with STEP AP242 ed2 PDM & geometric data model: it reuses concepts as Assembly structure, Part, Occurrence, Mating, Topology, Shape & Representation.

Electrical Wiring Harness extension is part of STEP AP242 e2 “International Standard” published in April 2020.

Example of associated use cases

  • Exchange of Electrical Harness information to harness manufacturer for manufacturing
  • Exchange of design information between Functional and Physical tool to insure the consistency of the design
  • Migration of Electrical Harness Design from a tool to another (CAD tool, Data base…)
  • Long term archiving of Electrical Harness design semantic data (for certification, maintenance, support in operation…)

Example of associated test cases



Dependencies / related standards

STEP AP 210 “Electronic assembly, interconnect, and packaging design

IEC 600050 International Electrotechnical Vocabulary (http://www.electropedia.org/):

  • Part 151: Electrical and magnetic devices
  • Part 212: Electrical insulating solids, liquids and gases
  • Part 442: Electrical accessories
  • Part 461: Electrical cables
  • Part 581: Electromechanical components for electronic equipment
  • Part 731: Superconductivity

Status of STEP AP242 ed2 Electrical Wiring Harness interface prototyping in COTS solutions

  • Core Technology pilot (CATIA V5 => 3D_Evolution => STEP AP242 ed2 xml => 3D_Evolution): development on going
  • Datakit pilot (UG- NX => STEP AP242 ed2 xml => 3D PDF): development on going


STEP AP242 ed2 pdf viewer of electrical wiring harness data developed by Datakit

Related Interoperability Forum: EWIS-IF

Composed of a:

  • A Users Group, composed of industries representatives, that defines the priorities of implementation of the STEP AP242 ed2 Electrical Harness interfaces through the definition of use cases & test cases. 
  • An Implementers Group, composed of electrical tools providers, that is in charge of:
    • The implementation & validation of STEP Electrical recommended practices
    • The Interoperability test round

Test rounds:

  • 1st test round launched in sept. 2019: 3 vendors involved, 2 test cases, based on STEP AP242 ed2 pre-IS version, results presented in March 2020
  • 2nd test round launched in sept. 2020: 4 vendors involved, 5 new test cases, based on STEP AP242 ed2 IS pre-amendment version, results planned to be presented in March 2021.

Recommended practices based on STEP AP242 e2 IS (including amendment in preparation) is in preparation by the EWIS-IF (https://www.cax-if.org/ewis/ewis_recommPractice.php)

Planned extensions in next AP242 editions for Electrical domain

  • Equipotential / signal concepts
  • Functional information: logical link, function, net…
  • EWIS requirements, safety rules,…
  • Optical fiber specificities