Which of the following is not a phase of the DMAIC process?

The correct answer is "Design" because the DMAIC process is specifically a structured problem-solving methodology used primarily for improving existing processes. DMAIC stands for Define, Measure, Analyze, Improve, and Control, which are the standard phases of this approach.

In the context of Six Sigma, "Design" pertains to a different methodology called DMADV (Define, Measure, Analyze, Design, Verify), which is used for developing new processes or products. Therefore, "Design" does not fit within the DMAIC framework, which focuses on refining and enhancing processes that are already in place, as opposed to creating new designs. The inclusion of the other phases, such as Measure, Control, and Analyze, emphasizes the importance of data collection, analysis, and maintaining improvements in existing processes.