DMAIC
Six Sigma improvement cycle: Define, Measure, Analyze, Improve, Control.
DMAIC is the structured five-phase improvement cycle that operationalizes Six Sigma project execution. Define identifies the problem, the customer, the team, scope, and goals. Measure baselines current performance and validates the measurement system itself. Analyze uses statistical and process tools to identify root causes of defects or variation. Improve develops, tests, and implements solutions, often using designed experiments. Control institutionalizes the improved process through control plans, control charts, and standard work to prevent regression. DMAIC descends from Shewhart's PDCA cycle (Plan-Do-Check-Act, popularized by Deming), with the Define and Measure phases providing more rigorous front-end discipline and Control replacing the simpler Act with explicit institutionalization mechanisms. The cycle is typically tied to Six Sigma project deliverables, belt-level execution, and tollgate reviews, and is widely used outside formal Six Sigma programs as a general structured improvement template.
Core components
- Define (problem, customer, scope, team, goals)
- Measure (baseline performance, MSA — measurement system analysis)
- Analyze (root cause identification using statistical and process tools)
- Improve (solution design, DOE — design of experiments, pilot)
- Control (control plan, control charts, standard work, training)
- Tollgate reviews between phases
- PDCA descent
Primary use case
Six Sigma project structure and execution; structured continuous-improvement initiatives outside Six Sigma; quality improvement in manufacturing, service, and transactional processes; foundation for Six Sigma belt training and certification.
Common criticisms
- Documentation and tollgate-review burden can stifle pace, particularly for smaller improvements
- rigid phase boundaries can prevent natural iteration between phases
- statistical sophistication requirement can be a barrier in smaller organizations
- tendency to apply DMAIC to problems that don't warrant it (the 'when you have a hammer' problem)
- Define phase often skipped or rushed, leading to solving the wrong problem rigorously
- less suited to genuinely novel problems where exploration is needed before measurement.
Lineage
- Child of
- Six Sigma
- Siblings
- DMADV, Six Sigma, Total Quality Management
- Derived from
- Six Sigma