I was really excited to find a book merging Six Sigma and Software Development, but after reading the book, I still have no idea "how" I would implement the methodology. Tayntor clearly understands the Six Sigma theory and practice, but fails to convice me of its relevance to system development life cycle (SDLC) models.
In the book, we learn the Six Sigma methodology, consisting of the steps "Define - Measure - Analyze - Improve - Control," works well for certain business models. The main goal of Six Sigma is to satisfy the "voice of the customer" or VOC. The VOC describes the needs or requirements of the customer. To ensure that outputs meet the customers' requirements, you must identify, quantify, and control the critical process inputs called X's. This control over the Xs reduces variation in the outcomes (or Y's).
For software developers, using Six Sigma to fully understand the Voice of Customer (VOC), means substantial savings and better overall product quality. Most costs overruns in software development are the result of poorly defined requirements. With Six Sigma and SDLC, the problem is implementation. We are not counting widgets, but discussing abstract intellectual processes. This a hard thing to quantify. I can count errors and I can reduce errors, but is bug free code necessarily good code?
Jeannine Siviy said it best when she described Six Sigma methods in manufacturing as "mature", but applications in software development are still "emerging".
If you are really trying to implement Six Sigma, I would recommend, Lean Software Development: An Agile Toolkit for Software Development Managers by Mary Poppendieck and Tom Poppendieck.
