As noted earlier, the Capability Maturity Model began as a process improvement framework for the field of technology engineering. The structure of the original CMM reflects that focus. But as the CMM's popularity grew, the SEI (and the CMM user community) began to see potential for applying the model to a broader group of IT activities. And so the SEI developed extensible forms of CMM, with the base version becoming know as the SW-CMM. A version was tailored for the processes and activities of systems engineering, known as the SE-CMM; a version was tailored to address the unique needs of strategic product and service acquisition (Supplier Sourcing); and a version was developed for the broad applicability of Integrated Product and Process Development, the IPPD-CMM.
Each of these models enjoyed acceptance and success in the various disciplines it addressed. Yet they all still retained many common elements. After a few years, many organizations that used all four disciplines began to ask for a model that capitalized on the common elements and at the same time allowed for a degree of flexible configurability. CMMI was the initiative to regroup these various tailored versions into a single, configurable model for all four disciplines. The Capability Maturity Model Integration represents the end result.
Today, CMMI-Dev v1.2 includes practices and program components for the following IT disciplines:
Systems engineering
Software engineering
Integrated product and process development
In CMMI, these disciplines are keyed to a series of Process Areas that contain the recommended practices that make the model work.
For IPPD, the full model applies—all Process Areas are relevant. IPPD is typically employed on only the largest of projects, or the most disparate, in which multiple organizations or reporting groups from different disciplines must be allied with a common vision to execute multiple project components in a highly coordinated manner.
For systems and software engineering, all Process Areas apply, with the exception of the IPPD principles and practices.
Practices for supplier sourcing are addressed under "Supplier Agreement Management," later in this chapter.