CMM
The Capability Maturity Model (CMM) of the Software Engineering Institute at Carnegie Mellon University describes the maturity of software development organisations on a scale of 1 to 5. It has been used extensively for avionics software and for government projects since it was created in the mid-1980s. The Software Engineering Institute has subsequently released a revised version known as the project management to track cost and schedule. The precise implementation differs from project to project within the organisation.
- CMM level 3 (defined): Software development across the organisation uses the same rules and events for project management. Crucially, the organization follows this process even under schedule pressures, ideally because management recognizes that it is the fastest way to finish.
- CMM level 4 (managed): Using precise measurements, management can effectively control the software development effort. In particular, management can identify ways to adjust and adapt the process to particular projects without measurable losses of quality or deviations from specifications.
- CMM level 5 (optimizing): Quantitative feedback from previous projects is used to improve the project management, usually using pilot projects, using the skills shown in level 4.
Anthony Finkelstien extrapolated that negative levels, or the Capability Immaturity Model, are necessary to represent environments that are not only indifferent, but actively counterproductive, and this was refined by Six Sigma quality of Deming fame). There is not particular evidence for shortening time to market, but there is for increasing the accuracy of estimating completion date from 75% overruns on average at level 1, to plus or minus 2% at level 5. Data on productivity increases is more variable, but it is at least a doubling of productivity.
Criticisms
The CMM does not describe how to create an effective software development organization. The traits it measures are in practice very hard to develop in an organization, even though they are very easy to recognize.
The CMM has been criticized for being overly bureaucratic and for promoting process over substance. In particular, for emphasizing predictability over service provided to end users. More commercially successful methodologies have focused not on the capability of the organization to produce software to satisfy some other organization or a collectively-produced specification, but on the capability of organizations to satisfy specific end user "use cases".
The CMM's division into levels has also been criticized in that it ignores the possibility that a single group may exhibit all of the behaviors and may change from
behavior to behavior over time. There is also the implication that a group must move from step to step and that it is impossible for a project group to move from one to five without going through intermediate steps.
The CMM is an important tool for outsourcing and exporting jobs. Economic development agencies in India, Ireland, and elsewhere have praised the CMM for enabling them to compete for US outsourcing contracts. This has been very positive for software engineers in emerging economies, especially in India. This has had severe consequences for software engineers in the USA and Europe.
See also
