CMM and PSP

In the late 1980s and early 1990s the SEI developed the Capability Maturity Model (CMM) which captured organizational best practices for software development. SEI Fellow Watts Humphrey decided to apply the underlying principles of the CMM to the software development practices of a single developer. The result of this effort was the Personal Software Process (PSP), designed to be a CMM level 5 process for individual software developers.

CMM and TSP

It soon became obvious that, while excellent results were possible using the PSP, it was almost impossible to maintain the discipline required for PSP practices if the surrounding environment did not encourage and demand them. Humphrey then developed the Team Software Process (TSP) for the smallest operational unit in most organizations, the project team. TSP was designed to be a CMM level 5 process for project teams. Recent results of using the TSP to achieve world-class quality levels while meeting cost and schedule estimates are documented in an SEI technical report.

Another SEI technical report maps the operational practices of the TSP to the practices spelled out in the SW-CMM v.1.1. Several organizations have used the TSP to move up the maturity ladder in much less time than reported averages, including one NAVAIR group that went from level 2 to level 4 in just 16 months largely on the strength of its TSP implementation.

Changes to CMM

In the meantime, the CMM’s success had led to the development of similar models addressing systems engineering (SE-CMM), integrated product development (IPD-CMM), software acquisition (SA-CMM), and human resources (People CMM). In order to alleviate at least some of the proliferation of models, SEI produced the Capability Maturity Model Integration (CMMI), using as its source models the never-published CMM version 2 for software, SE-CMM, and IPD-CMM.

Mapping TSP and CMMI

The SEI released a technical report in 2004, Mapping TSP to CMMI. Early indications from this effort are that, while some of the "new" practices from the SE-CMM and IPD-CMM are not addressed by the TSP, many of them are, which—in combination with the large number of similar practices from the venerable SW-CMM—leads to the conclusion that TSP is a practical, accessible method for achieving the benefits of high maturity process on a much accelerated schedule.