DMAIC

DMAIC is the core Six Sigma methodology for improving an existing process, structured as five sequential phases.

The idea

Each letter is a phase. Define the problem and goals. Measure current performance with real data. Analyze the data to find root causes of variation or defects. Improve the process by testing and implementing fixes. Control the improved process so gains stick, typically with monitoring and standard work. The cycle assumes the process already exists. DMADV and DFSS, its cousins, design a new process from scratch.

When to use it

• An existing process has a measurable quality, cost, or speed problem.
• Data can realistically be collected on the process.
• The organization needs a repeatable, disciplined structure rather than an ad-hoc fix.

How to apply it

1. Define the problem. Write a problem statement, scope, and goal.
2. Measure current performance. Map the process and collect baseline data.
3. Analyze the data. Use root-cause techniques to isolate the real drivers of the problem.
4. Improve the process. Generate, test, and pilot changes before rolling them out.
5. Control the gains. Put monitoring, documentation, and ownership in place so the improvement holds.

Watch out for

Skipping straight to “Improve” without solid Measure and Analyze data is the most common failure. It produces fixes for the wrong problem. The Control phase is also often neglected, letting the process drift back to its old state.

Related models

• Design for Lean Six Sigma. The related Design for Lean Six Sigma approach for new processes.
• Root Cause Analysis. The technique underlying the Analyze phase.
• Kaizen. A complementary philosophy of continuous, incremental improvement.

Sources

Six Sigma methodology, originally developed at Motorola and popularized by General Electric.