DMAIC is the improvement cycle at the centre of Six Sigma. It runs a project through five phases in order, each with an exit condition that has to be met before the next begins.
Define establishes what problem is being solved, for whom, and what better would look like in measurable terms. The output is a scoped problem statement, not a hypothesis about the cause. Measure establishes the current state with data rather than opinion, which includes checking the measurement system itself — a project built on an unreliable gauge fails regardless of how good the later analysis is.
Analyse identifies what is actually driving the problem. Most failed projects fail here, by assuming a cause early and spending the remaining phases confirming it. Improve designs and tests changes against those causes; testing before full deployment is what separates this from ordinary problem solving. Control makes the change the new normal through standards, monitoring and a defined response to drift.
It suits problems where the cause is genuinely unknown and the process already exists. Where the cause is known and the fix obvious, DMAIC is overhead. Where the process does not exist yet, DMADV applies instead.
Skipping Control is why so many organisations can point at improvements that no longer hold.
