AP203ed2 conformance classes

From WikiSTEP

A decision was made that AP203ed2 will not have conformance classes.
So the below is only a history record of ideas.

Conformance classes are defined in clause 6 of every STEP-AP. For the modular APs the content of a conformance class is defined by an implementation module (the other modules are foundation modules).

AP203ed1 had originally 6 conformance classes. Because cc1 was too big to be implemented by mechanical CAD systems, this got split into cc1a and cc1b by TC2. This split was then tracked further through all of the geometric conformance classes cc2 to cc6, resulting int a total of 12 conformance classes (see below). In the 2005/TS version no conformance classes were defined, but now for the 2nd edition it is agreed to re-introduce them.

conformance classes as defined in AP203ed1/TC2

• 1a: Product identification without shape;
• 1b: Configuration-controlled design information without shape
• 2a: Class 1a and shapes represented by geometrically bounded wireframe models, surface models, or both
• 2b: Class 1b and shapes represented by geometrically bounded wireframe models, surface models, or both
• 3a: Class 1a and shapes represented by wireframe models with topology
• 3b: Class 1b and shapes represented by wireframe models with topology
• 4a: Class 1a and shapes represented by manifold surface models with topology
• 4b: Class 1b and shapes represented by manifold surface models with topology
• 5a: Class 1a and shapes represented by faceted b-rep
• 5b: Class 1b and shapes represented by faceted b-rep
• 6a: Class 1a and shapes represented by advanced b-rep
• 6b: Class 1b and shapes represented by advanced b-rep

Conformance class modules for AP203ed2

Conformance classes are defined from a non CAx-expert perspective. Those people don't know about the different kinds of geometric models. But because not all systems are supporting all kinds of models we have then to introduce mandatory and optional functionality.

• Mechanical_part_with_3D_model: Almost equivalent to AP214cc1 "Conformance Class for component design with 3D shape representation". Most CAx system support assemblies, but not all, e.g. TolTool or CATIA v4.
• Mechanical_part_and_assembly_with_3D_model: Almost equivalent to AP214cc2 "Conformance Class for assembly design with 3D shape representation". This adds assemblies to Mechanical_part_with_3D_model. It is the core conformance class being supported by many mechanical CAD systems today.
• Mechanical_part_with_construction_history_based_3D_model: This adds construction history to Mechanical_part_with_3D_model.
• Mechanical_part_with_3D_model_and_tolerance_data: This adds GD&T to Mechanical_part_with_3D_model.
• Mechanical_part_with_annotated_3D_model_and_tolerance_data: This adds annotations to Mechanical_part_with_3D_model_and_tolerance_data to support exchange of "annotated model" data sets according to ISO 16792 (maybe not fully completely)
• Mechanical_part_with_styled_3D_model: This adds styling like colors and shading to Mechanical_part_with_3D_model. It wraps up the functionality of AIC517
• Product_data_management_with_external_geometric_model: Almost equivalent to AP214cc6 "Conformance Class for product data management without shape representation".
• Configuration_controlled_design__with_external_geometric_model: Almost equivalent to AP214cc8 "Conformance Class for configuration controlled design without shape representation".
• Configuration_controlled_3d_design: The top AP203 module including everything. Providing the only one long-form to use.

Implementations may claim conformance to more than one conformance class

Topics for which not to create extra conformance-class modules

• old conformance classes 2 to 6 for single geometric models
• presentation without GD&T