Where do I start? It’s a question each of us asks when faced with any learning goal, whether it’s how to play ‘Stairway to Heaven’ on a guitar, or how to deploy a database. The answer, as any teacher will tell you, is to work out where you are now, in terms of skills and equipment, and then what you need to do in order to reach the next level. Each step has to be challenging enough to keep your attention, yet not so hard as to be discouraging.

The Capability Maturity Model uses this principle to help people plan out, step-by-step, how to increase the quality of any broad process area, such as software governance, or continuous delivery. For a given process area, it establishes a skills-versus-maturity matrix. Each column identifies a required skill, or working method, and each of 5 rows identifies progressive stages of maturity, and the goals, practices and behaviors that characterize each stage.

The Initial stage involves ad-hoc techniques, chaotic progress, and the inevitable late night heroics to hit a project deadline. At the Repeatable stage, a working method is documented to the point that it can be repeated. By the third stage, Defined, it is established as a standard business processes, and at the fourth, Managed, it is managed and measurable. Finally comes the Optimizing stage where the team make the incremental, often innovative, improvements that become possible when a process is automated, predictable and measured.

The matrix was originally devised by the US Department of Defense as a measure of the “fitness for purpose” of software manufacturing processes, and the software contractors who used it were surprised by its effectiveness. It eventually became standard practice for software project managers, and has also helped organizations achieve continuous delivery of their software products. The levels and some of aged and slightly controversial ‘characteristic practices’ of the CMM were replaced by those more relevant, but the underlying concept was simple and unchanging: for a given skill or method, use the matrix to identify where you are now and what to aim for next.

The CMM has been criticized for ignoring the fact that in many cases the great breakthroughs in software have been achieved by creative and disobedient mavericks who recoil from the established software engineering principles, and stay up all night coding whilst eating Pizza and drip-feeding caffeine. Although the CMM doesn’t particularly object to talented developers working heroically, it prefers to rely on methods that are more likely to deliver the right software at the expected time. It is a different world from the startup.

The sort of developer who wears his metaphorical underpants outside his metaphorical trousers will have no use for a CMM, but generally businesses thrive on stable processes that are visible, predicable and repeatable. There is always room for a maverick hero in any enterprise, but the CMM is based on the dull but sensible assumption that large commercial or government software projects are best produced by teams working with sound, repeatable processes. It is a sad fact that many recent software projects, government or otherwise, have eschewed even the most basic lessons of the CMM, with predictable consequences.