AP 223, Exchange of design and manufacturing product information for cast parts AP 224, Mechanical product definition for process plans using machining features AP 238 - Application interpreted model for computer numeric controllers AP 240, Process plans for machined products Life cycle support APs: AP 239, Product life cycle support AP 221, Functional data and schematic representation of process plants AP 241, Generic Model for Life Cycle Support of AEC Facilities (planned) The AP 221 model is very similar to the ISO 15926-2 model, whereas AP 221 follows the STEP architecture and ISO 15926-2 has a different architecture. They both use ISO-15926-4 as their common reference data library or dictionary of standard instances. A further development of both standards resulted in Gellish English as general product modeling language that is application domain independent and that is proposed as a work item (NWI) for a new standard. The original intent of STEP was to publish one integrated data-model for all life cycle aspects. But due to the complexity, different groups of developers and different speed in the development processes, the splitting into several APs was needed. But this splitting made it difficult to ensure that APs are interoperable in overlapping areas. Main areas of harmonization are: AP 212, 221, 227 and 242 for technical drawings with extension in AP 212 and 221 for schematic functionality AP 224, 238 and 242 for machining features and for Geometric dimensioning and tolerancing For complex areas it is clear that more than one APs are needed to cover all major aspects: AP 212 and 242 for electro-mechanical products such as a car or a transformer. This will be addressed by the second edition of AP242 that is currently under development AP 242, 209 and 210 for electro/electronic-mechanical products AP 212, 215, 216, 218, 227 for ships AP 203/214, 224, 240 and 238 for the complete design and manufacturing process of piece parts. See also Boundary representation Geometric dimensioning and tolerancing ISO 16739 Industry Foundation Classes, widely used instead of ISO 10303-225 Notes References External links Standardization group ISO TC184/SC4 List of STEP parts STEP Ship team ISO TC 184/SC 4/WG 3/T 23 STEP AP242 Project The STEP Module Repository on SourceForge CAx Implementor Forum - information on existing implementations and testing activities WikiSTEP - tutorial and overview information about STEP and recommended practices PDES, Inc. - recommended practices and links Korea STEP Center Product Life