CMMI stands for Capability Maturity Model Integration.
There is also CMM (Capability Maturity Model), but it has been largely supersede by CMMI. The major difference between these two is that CMM focuses on isolated processes, whereas CMMI focuses on the integration among those processes.
CMMI establishes 5 maturity stages on processes:
- Initial
- Managed (“repeatble” in CMM)
- Defined
- Quantitatively managed (“managed” in CMM)
- Optimized
CMMI is used on GAP analysis, to identify the current state and the objective state.
The implementation of CMMI processes facilitates the implementation of controls for ISO/IEC 27002.
There are various certification levels for CMMI practitioners:
https://cmmiinstitute.com/learning/certifications
There is a CMMC, for Cybersercuty Capability Maturity Model.