STEP AP242 protocol

Last updates of STEP AP203 (E2) and AP214 (E3) have been published in 2009.
A new evolution of STEP has been published on end 2014 : AP242. It is espscially motivated by the needs of long term archiving of CAD data.
It results from an initiative promoted by LOTAR group, to favour a common effort as an alternative to parallel works on AP203 and AP214, resulting in a convergent application protocol.

This initiative has defined a new protocol : AP242, "Managed Model Based 3D Engineering", harmonized with AP203, AP214 and other widely used STEP protocols. It is mainly aimed to :

• introduce new capabilities of exchanging and archiving CAD data (case coverage),
• make them harmonized with existing STEP protocols (including AP203, AP214) and other standards involved in CAD (ASME, ISO in particular for PMI…),
• optimize the work load and agenda of standardization and specification,
• make STEP easier to support and use in the industrial world,
• improve efficiency of processes by integrating the various enterprise functions.

As the last editions of STEP protocols, its definition is modular, allowing further evolution and enhancements in a more flexible way.
It gather the definitions in both AP203(E2) and AP214(E3), and extend them to new topics.
Among the planned extension of case coverage, we can notice :

• completions to PMI (including surface conditions, PMI in assembly), machining features,
• tessellation, allowing STEP to support a light visualization model in an efficient way,
• composite structures, electrical harness and piping,
• domain of PDM (Business Object Model),
• product data quality (quality criteria and check results),
• mechatronics
• and other topics involved in systems engineering integration.

This introduces new definitions (entity types), and also a new mechanism allowing to describe references between elements of several model written on separate files (external element references). As for instance for a dimension defined in an assembly, between two faces of two instantiated components.

A strong request is to have this new protocol soon available. In order to do so, the works of standardization are expected to be completed by validation works, to have the standard and its use rules jointly available, and help speeding up the implementation of software solutions.

AP242 is designed modular, with regular increments in order to bring added value to users. A first edition (AP242E1) brings a first set of new features (overall for PMI, tessellation, external element references). A second edition (AP242E2) is in preparation to complete the case coverage.

As taking part in the work on long term archiving of the LOTAR group, DATAKIT is involved in works on AP242

• from the start of AP242, pilot projects, actions of tests and validation.
• for AP242 Edition 2 (AP242E2), participation in works groups (in particular geometry, PMI).

A public presentation of the STEP AP242 project can be seen on line : site of STEP AP242 Project.

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