Translations:CMM-SW/3/en
It was designed in the late 1980s by the Software Engineering Institute (SEI) at the request of the United States Congress, as a tool for assessing the Department of Defense's software suppliers. Its first version was published in 1991, and it was revised in 1993 (v1.1) and 1997 (v1.2). In 2000 it was superseded by and integrated into the new CMMI model.

The five maturity levels
Level 1: Initial
The quality achieved depends on people and the tools they use, not on processes. Either there are no defined processes, or they are not followed consistently. Results are unpredictable and depend on individual talent.
Level 2: Repeatable
Basic project management practices are carried out: requirements management, version control, progress tracking, and subcontractor management. Teams can draw on practices carried out in previous projects and apply them to new ones.
Level 3: Defined
Common development and maintenance processes are documented in a library accessible to all teams. People have been trained to understand and apply them. For each project, the standard processes are tailored to the needs of the case while maintaining a consistent foundation.
Level 4: Managed
The organization measures product and process quality quantitatively through established metrics. Process capability is predictable, and the measurement system makes it possible to detect variations outside acceptable ranges so that corrective action can be taken.
Level 5: Optimizing
Continuous process improvement extends across the entire organization, which has the means to identify weaknesses and strengthen defect prevention. Data on process effectiveness is systematically analyzed to evaluate the cost and benefit of adaptations and improvements.