Introduction to CMMI


The TMMi Professsional syllabus states that students must have an understanding of how CMMI works to be able to understand the links with TMMi.

The CMMi model has both a staged and continuous representation model. The differences between them are are subtle but significant.

Staged representation

In the staged representation there are prescribed, ordered, stages that an organisation must go through to improve its development process (i.e. Maturity Levels). It is organisational maturity that is the focus of the staged representation. It provides a proven sequence of improvements that is a foundation for the next one and enables organisations to compare Maturity Levels by using a common rating.

Continuous representation

In the continuous representation there are no fixed levels or stages to go through and organisations can select areas for improvement from different categories according to their perceived need. Process Area capability is the focus of the continuous representation. Using the continuous representation allows the selection of the order of improvement that best meets the organisational goals and addresses specific areas of risk. It also allows organisations to compare at Process Area level.

Selecting a CMMi model

There are various reasons for selecting one or other of the representations. Some organisations may choose the one with which they are most familiar.

Benefits of the staged model

  • It provides a proven sequence of improvements
  • It starts with basic management practices and progresses through a proven, pre-defined path of a sucession of Levels
  • Each Level provides a foundation for the next one
  • It gives a single rating summarising assessment results
  • It enables comparison across and among organisations by means of Maturity Levels
  • It also provides an easy migration from SW-CMM to CMMI

Benefits of the continuous model

  • It allows selection of the order of improvement that best meets the business objectives of the organisation
  • It allows mitigation of specific areas of the organisation’s risk
  • It enables comparisons across and among organisations Process Area by Process Area or by comparing results by equivalent staging

The TMMi currently follows only a staged representation, but in the future there may be the option to use a continuous approach.