Editing Capability Maturity Model (section)

===Levels===
There are five levels defined along the continuum of the model and, according to the SEI: "Predictability, effectiveness, and control of an organization's software processes are believed to improve as the organization moves up these five levels. While not rigorous, the empirical evidence to date supports this belief".<ref>[http://www.michigan.gov/documents/CMM_39213_7.pdf State of Michigan SDLC Appendix on CMM] Attests to 2001 use of the text so it couldn't have come from here.</ref>
# ''Initial'' (chaotic, ad hoc, individual heroics) - the starting point for use of a new or undocumented repeat process.
# ''Repeatable'' - the process is at least documented sufficiently such that repeating the same steps may be attempted.
# ''Defined'' - the process is defined/confirmed as a standard [[business process]]
# ''Capable'' - the process is quantitatively managed in accordance with agreed-upon metrics.
# ''Efficient'' - process management includes deliberate process optimization/improvement.

Within each of these maturity levels are Key Process Areas which characterise that level, and for each such area there are five factors:  goals,  commitment,  ability,  measurement,  and verification. These are not necessarily unique to CMMI, representing — as they do — the stages that organizations must go through on the way to becoming mature.

The model provides a theoretical continuum along which process maturity can be developed incrementally from one level to the next. Skipping levels is not allowed/feasible.

; Level 1 - ''Initial'': It is characteristic of processes at this level that they are (typically) undocumented and in a state of dynamic change, tending to be driven in an ''ad hoc'', uncontrolled and reactive manner by users or events. This provides a chaotic or unstable environment for the processes. (Example - a surgeon performing a new operation a small number of times - the levels of negative outcome are not known).

; Level 2 - ''Repeatable'': It is characteristic of this level of maturity that some processes are repeatable, possibly with consistent results. Process discipline is unlikely to be rigorous, but where it exists it may help to ensure that existing processes are maintained during times of stress.

; Level 3 - ''Defined'': It is characteristic of processes at this level that there are sets of defined and documented standard processes established and subject to some degree of improvement over time. These standard processes are in place. The processes may not have been systematically or repeatedly used - sufficient for the users to become competent or the process to be validated in a range of situations.  This could be considered a developmental stage - with use in a wider range of conditions and user competence development the process can develop to next level of maturity.

; Level 4 - ''Managed (Capable)'': It is characteristic of processes at this level that, using process metrics, effective achievement of the process objectives can be evidenced across a range of operational conditions. The suitability of the process in multiple environments has been tested and the process refined and adapted.  Process users have experienced the process in multiple and varied conditions, and are able to demonstrate competence.  The process maturity enables adaptions to particular projects without measurable losses of quality or deviations from specifications. Process Capability is established from this level. (Example - surgeon performing an operation hundreds of times with levels of negative outcome approaching zero).

; Level 5 - ''Optimizing (Efficient)'':It is a characteristic of processes at this level that the focus is on continually improving process performance through both incremental and innovative technological changes/improvements. At maturity level 5, processes are concerned with addressing statistical ''common causes'' of process variation and changing the process (for example, to shift the mean of the process performance) to improve process performance. This would be done at the same time as maintaining the likelihood of achieving the established quantitative process-improvement objectives.

Between 2008 and 2019, about 12% of appraisals given were at maturity levels 4 and 5.<ref>{{Cite web|url=https://cmmiinstitute.com/resource-files/public/cmmi-adoption-trends-2019-mid-year-update|title=CMMI Adoption Trends - 2019 Mid Year Update|date=2019-10-21|website=CMMI Institute}}</ref><ref>{{Cite web|url=https://www.fastcompany.com/28121/they-write-right-stuff|title=They Write the Right Stuff|last=Fishman|first=Charles|date=1996-12-31|website=Fast Company|language=en-US|access-date=2020-02-15}}</ref>