Examination of a defined function to identify all the subfunctions necessary to the accomplishment of that function; identification of functional relationships and interfaces (internal and external) and capturing these in a functional architecture; and flow down of upper level performance requirements and assignment of these requirements to lower level subfunctions. (See “functional architecture.”)

1. This glossary is from Appendix C of Technical Report CMU/SEI-2002-TR-004.
2. ® CMMI is registered in the U.S. Patent and Trademark Office by Carnegie Mellon University.