The core metamodel provides a minimum set of architectural content to support traceability across artifacts. Additional metamodel concepts to support more specific or more in-depth modeling are contained within a group of extensions that logically cluster extension catalogs, matrices, and diagrams, allowing focus in areas of specific interest and focus.

All extension modules are optional and should be selected during the Preliminary Phase of the architecture development to meet the needs of the organization. Additionally, the extension groupings described by the content metamodel are only a suggestion and further tailoring may be carried out to suit the specific needs at the discretion of the architects.