Specification of the Asset Administration Shell Welcome to the home of the specification of the Asset Administration Shell Refer to the IDTA for more information on the Asset Administration Shell. Part 1: Metamodel The Metamodel of the AAS. Part 2: Application Programming Interfaces The API of the AAS. Part 3a: Data Specification - IEC61360 The data specification IEC61360 of the AAS. Part 4: Security The security for the AAS and its submodels. Part 5: Package File Format (AASX) The AASX file format of the AAS.