DMAIC Demystified
The DMAIC (Define-Measure-Analyze-Improve-Control) methodology is one of the cornerstones of a Six Sigma project. It provides a useful heuristic that can remind you how to structure your project when you apply Six Sigma. This is important for two reasons. First, by reminding you to DEFINE your project’s goals, its deliverables to external customers, its deliverables to internal customers, and most important – your definition of a defect – you establish the solid foundation for actually delivering process improvements that meet tangible goals. Second, DMAIC provides a common language for Six Sigma practitioners so that new teams can spend time solving problems instead of searching for their own standard operating procedures.
If you’re familiar with Deming’s PDCA (Plan-Do-Check-Act) cycle, DMAIC is essentially equivalent, but with a very important addition at the end:
- Planning = Defining
- Doing = Measuring
- Checking = Analyzing
- Acting = Improving
- (Sustaining/Continually Learning) = Controlling
There’s nothing magical about DMAIC – it’s just a helpful reminder to guide you as you structure a Six Sigma project. And remember that a Six Sigma project is hopefully not the end of the improvement – ideally, a process team will leave behind a new foundation for identifying more efficiencies in the future.
As a rough sketch of PDCA/PDSA and DMAIC, I like your model. But I think Doing really doesn’t equal Measuring at all. A major distinction between PDCA and DMAIC is the care with which Six Sigma people:
a) Ensure their measurement system is useful
b) Test hypotheses and have degrees of certainty about making an improvement before making a change
PDCA isn’t so careful – usually doing is about just trying something, anything, and seeing if that seemed to make an outcome better.
I do agree with you that the Control phase – sustaining the gains – is different than PDSA. I think it’s also worthwhile to point out that DFSS (DMADV) is a wholesale different approach to designing a new process or product/service that reuses some, but adds many tools that go beyond DMAIC.
Do and Measure isn’t the SAME.Typically, checking measurement integrity is the most unpopular step for a practitioner. However, measuring how well the process is doing lead to a successful project blueprint.