Implementing Six Sigma for Software

In our experience with implementing Six Sigma for software we found the following three principles most useful:
Principle No 1: Measure customer related metrics only
- Use Combinatory Metrics to cover all topics
Principle No 2: Adjust to moving targets
- Your goals may need change; accept change and manage it accordingly
Principle No 3: Enforce measurement
- Do not enforce meeting targets

The last principle is the most difficult one, because this is against the project manager’s carnet of duties.Indeed, this is what most often goes wrong in software projects: People want to enforce targets and consequently miss the goals. This is because setting targets that really lead to the goal is so difficult in software projects.
Just consider the ever-lurking dilemma: Should we make the milestones, or do it right the first time such that we can later use the knowledge gained to proceed faster? Writing or implementing software is not just an engineering discipline but in essence it is knowledge transfer.