CMM... acts as a health capsule in determining and maintaining the overall quality of the organisation....

Dr William Edward Deming of Total Quality Management fame once opined:  "Quality isn't about people doing their best, it's about having the right process in place such as when people understand them, then they can do their best within the system." In today's ever-competitive markets, quality-conscious customers look for maximum value for their money. In the context of the software industry, quality consciousness level is even higher.

The Capability Maturity Model (CMM) is a methodology used to develop and refine an organization's software development process. The model describes a five-level evolutionary path of increasingly organized and systematically more mature processes. CMM was developed and is promoted by the Software Engineering Institute (SEI), a research and development center sponsored by the U.S. Department of Defense (DoD). SEI was founded in 1984 to address software engineering issues and, in a broad sense, to advance software engineering methodologies. More specifically, SEI was established to optimize the process of developing, acquiring, and maintaining heavily software-reliant systems for the DoD. Because the processes involved are equally applicable to the software industry as a whole, SEI advocates industry-wide adoption of the CMM.

Capability Maturity Model (CMM) broadly refers to a process improvement approach that is based on a process model. CMM also refers specifically to the first such model, developed by the Software Engineering Institute (SEI) in the mid-1980s, as well as the family of process models that followed. A process model is a structured collection of practices that describe the characteristics of effective processes; the practices included are those proven by experience to be effective.

The Capability Maturity Model was initially funded by military research. The United States Air Force funded a study at the Carnegie-Mellon Software Engineering Institute to create a model (abstract) for the military to use as an objective evaluation of software subcontractors. The result was the Capability Maturity Model, published as Managing the Software Process in 1989. The CMM is no longer supported by the SEI and has been superseded by the more comprehensive Capability Maturity Model Integration (CMMI).

A maturity model can be viewed as a set of structured levels that describe how well the behaviours, practices and processes of an organisation can reliably and sustainably produce required outcomes. A maturity model may provide, for example :

§  a place to start

§  the benefit of a community’s prior experiences

§  a common language and a shared vision

§  a framework for prioritizing actions.

§  a way to define what improvement means for your organization.

In any software development company there are standards for processes of development, testing, and software application; and rules for appearance of final program code, components, interfaces, etc.

The CMM model defines five levels of organizational maturity:

1. Initial level is a basis for comparison with the next levels. In an organization at the initial level, conditions are not stable for the development of quality software. The results of any project depend totally on the manager’s personal approach and the programmers’ experience, meaning the success of a particular project can be repeated only if the same managers and programmers are assigned to the next project. In addition, if managers or programmers leave the company, the quality of produced software will sharply decrease. In many cases, the development process comes down to writing code with minimal testing. 

2. Repeatable level. At this level, project management technologies have been introduced in a company. That project planning and management is based on accumulated experience and there are standards for produced software (these standards are documented) and there is a special quality management group. At critical times, the process tends to roll back to the initial level. 

3. Defined level. Here, standards for the processes of software development and maintenance are introduced and documented (including project management). During the introduction of standards, a transition to more effective technologies occurs. There is a special quality management department for building and maintaining these standards. A program of constant, advanced training of staff is required for achievement of this level. Starting with this level, the degree of organizational dependence on the qualities of particular developers decreases and the process does not tend to roll back to the previous level in critical situations. 

4. Managed level. There are quantitative indices (for both software and process as a whole) established in the organization. Better project management is achieved due to the decrease of digression in different project indices. However, sensible variations in process efficiency may be different from random variations (noise), especially in mastered areas.

5. Optimizing level. Improvement procedures are carried out not only for existing processes, but also for evaluation of the efficiency of newly introduced innovative technologies. The main goal of an organization on this level is permanent improvement of existing processes. This should anticipate possible errors and defects and decrease the costs of software development, by creating reusable components for example.

A critical distinction between maturity level 4 and maturity level 5 is the type of process variation addressed. At maturity level 4, processes are concerned with addressing special causes of process variation and providing statistical predictability of the results. Though processes may produce predictable results, the results may be insufficient to achieve the established objectives. At maturity level 5, processes are concerned with addressing common causes of process variation and changing the process (that is, shifting the mean of the process performance) to improve process performance (while maintaining statistical probability) to achieve the established quantitative process-improvement objectives.

It can be concluded that CMM helps in judging the software processes of an organization as well as identifying the prerequisites necessary to enhance the overall maturity level of these processes. It furthermore points the way down a well-defined path to improve the management and development of software products in a disciplined and orderly way. Applied in a proper manner, CMM is indeed a powerful system, which can help transform an IT organization and help it to reach its pinnacle.