Which is NOT a phase of the six sigma methodology?

The six sigma methodology consists of five specific phases known as DMAIC: Define, Measure, Analyze, Improve, and Control. Each of these phases plays a critical role in process improvement and quality management. It begins with defining the problem, measuring the current process performance, analyzing data to identify root causes, improving the process based on the analysis, and controlling future performance to sustain improvements.

The term “Plan,” while it may seem related to aspects of project management or quality improvement, does not align with the established phases of six sigma. Including it in the list suggests a misunderstanding of the systematic approach taken in six sigma, which emphasizes a structured process for achieving quality improvements through the DMAIC framework.