What is the Capability Maturity Model (CMM)

What is the Capability Maturity Model (CMM)?

CMM is a framework set by SEI, which provides a general roadmap for process improvement. Software Process Capability describes the range of expected results that can be achieved by following the process. The process capability of an organization determines what can be expected from the organization in terms of quality and productivity. The goal of process improvement is to improve the process capability.

A maturity level is a well-defined evolutionary plateau toward achieving a mature software process. There are five well-defined maturity levels for a software process. These are:

Initial
Repeatable
Defined
Managed
Optimizing

The Initial Process (Level 1) is essentially an ad hoc process that has no formalized method for any activity. Basic project controls for ensuring that activities are being done properly and that the project plan is being adhered to are missing. In crisis the project plans and development processes are abandoned in favor of a code and test type of approach. Success in such organizations depends solely on the quality and capability of individuals. The process capability is unpredictable as the process constantly changes. Organizations at this level can benefit most by improving project management, quality assurance, and change control.

The Repeatable process (Level 2) policies for managing a software project and procedures to implement those policies exist. Project management is well developed in a process at this level. Some of the characteristics of a process at this level are: project commitments are realistic and based on past experience with similar projects, cost and schedule are tracked and problems resolved when they arise, formal configuration control mechanisms are in place, and software project standards are defined and followed. Essentially, results obtained by this process can be repeated as the project planning and tracking is formal.

The Defined process (Level 3) in an organization has standardized on a software process, which is properly documented. A software group exists in the organization that owns and manages the process. In the process each step is carefully defined with verifiable entry and exit criteria, methodologies for performing the step, and verification mechanisms for the output of the step. In this process both the development and management processes are formal.

In the Managed process (Level 4) quantitative goals exist for process and products. Data is collected from software processes, which is used to build models to characterize the process. Hence, measurement plays an important role in a process at this level. Due to the models build, the organization has a good insight in the process and its deficiencies. The results of using such a process can be predicted in quantitative terms.

In the Optimizing process (Level 5), the focus of the organization is on continuous process improvement. Data is collected and routinely analyzed to identify areas that can be strengthened to improve quality or productivity. New technologies and tools are introduced and their effects measured in an effort to improve the performance of the process. Best software engineering and management practices are used throughout the organization.