Take a look at the latest, dorky, BD00 diagram below. The process model on the left is derived from the meaty, 482 page CMMI-DEV SEI Technical Report. The model on the right is derived from the lean, 16 page Scrum Guide.
Comparing CMMI-DEV and Scrum may seem like comparing apples to oranges, but it’s my blog and I can write (almost) whatever I want on it, no?
Don’t write what you know, write what you want to know – Jerry Weinberg
The overarching purpose of both process frameworks is to help orgs develop and sustain complex products. As you can deduce, the two approaches for achieving that purpose appear to be radically different.
The CMMI-DEV model is comprised of 22 practice areas, each of which has a number of specific and generic practices. Goodly or badly, note that the word “practice” dominates the CMMI-DEV model.
Unlike the “practice” dominated CMMI-DEV model, the Scrum model elements are diverse. Scrum’s first class citizens are roles (people!), events, artifacts, and the rules of the game that integrate these elements into a coherent socio-technical system. In Scrum, as long as the rules of the game are satisfied, no practice is off limits for inclusion into the framework. However, the genius inclusion of time limits for each of Scrum’s 4 event types implicitly discourages heavyweight practices from being adopted by Scrum implementers and practitioners.
Of course, following either model or some hybrid combo can lead to product quality/time/budget success or failure. Aficionados on both sides of the fence publicly tout their successes and either downplay their failures (“they didn’t understand or really follow the process!“) or they ignore them outright. As everyone knows, there are just too many freakin’ metaphysical factors involved in a complex product development effort. Ultimately and unsurprisingly, success or failure comes down to the quality of the people participating in the game – and a lot of luck. Yawn.