First project activities were focused on the harmonization of the information model to be shared by AP239 ed 3 with other STEP Application Protocols (including AP242 ed2).
This is seen as a key step towards interoperability between STEP Application Protocols (APs), and as an anabler for the "Through life cycle interoperability" targetted by stakeholders (industry and governmental agencies).
This work is conducted in the context of "STEP enhanced architecture", delivering the "Core model", a set of Core Technical Capabilities (CTCs) descibed in SysML langage and mapped to the STEP Application Reference Model (ARM). The model-based approach provided by the "STEP enhanced architecture" is seen as a significant step forward, as mappings from business objects to the underliying information components will be supported by SysML diagrams, enabling consistency and increased quality.
The Core model, also known as 10303-4000 or Part 4000, is to be published by ISO as a Technical Specification (TS). Several cumulative versions are planned, the first version of the Core Model Technical Specification integrating the CTCs that are shared by AP242 and AP239 plus CTCs required for AP243 (MoSSEC).

NB: each AP will have its own Domain Model, mapped to the Core model.
This harmonization work aims also at enabling the linkage between AP239 ed3 and the ILS specifications (AIA-ASD S-Series and SAE GEIA-STD-0007), to be done through the future AP239 ed3 Domain Model.