CMMI- An overview

The CMMI is a framework for business process improvement. In other words, it is a model for building process improvement systems. In the same way that models are used to guide thinking and analysis on how to build other things (algorithms, buildings, molecules), CMMI is used to build process improvement systems.

CMMI (Capability Maturity Model Integration) was formed after merging multiple CMM models - Capability Maturity Model for Software(SW-CMM), Systems Engineering Capability Model(SECM), Integrated Product Development Capability Maturity Model (IPD-CMM). As managing multiple CMM models is difficult, SEI integrated all CMM models into one - CMM Integrated. The structure and essence of CMMI is same as that of CMM.

There are 5 levels of maturity in CMMi, each layer is the foundation for ongoing improvement, designated by numbers 1 through 5,befor getting itnto that we need to understand PA or Process Areas.

A process area is a cluster of related practices in an area that, when implemented collectively, satisfy a set of goals considered important for making improvement in that area.

Level 1 : Initial or Ad-hoc. There are no PAs (Process Areas) in this level
Level 2 : Managed. There are 7 PAs. PAs at this level look at project planning and execution (Basic project management)
Level 3 : Defined. There are 11 PAs here. Life cycle processes and Organizational processes are the focus areas here.
Level 4 : Quantitatively Managed. There are 2 PAs that deal with project management with quantitative data and statistical process control. (SPC)
Level 5 : Optimizing. There are 2 PAs. The focus is on continuous improvement.

There are 22 process areas in all.
As we move from Level 1 to 5, the project risk decreases & Quality and Productivity increases.

What are the characteristics of a mature organization ?

Organizations can achieve progressive improvements in their organizational maturity by achieving control first at the project level and continuing to the most advanced level—organization-wide continuous process improvement—using both quantitative and qualitative data to make decisions.

A mature software organization possesses an organization-wide ability for managing software development and maintenance processes. The software process is accurately communicated to both existing staff and new employees, and work activities are carried out according to the planned process. The processes mandated are fit for use and consistent with the way the work actually gets done. These defined processes are updated when necessary, and improvements are developed through controlled pilot-tests and/or cost benefit analyses. Roles and responsibilities within the defined process are clear throughout the project and across the organization.

The CMM / CMMI model was designed to guide software organizations in selecting process improvement strategies by determining current process maturity and identifying the few issues most critical to software quality and process improvement.

What's the difference between Maturity Level and Capability Level?

They are different ways of rating your processes.

A "Maturity Level" is what you can be appraised to and rated as when the organization uses the Staged Representation of the CMMI, and a "Capability Level" is what you can be appraised to and rated as when the organization uses the Continuous Representation of the CMMI.