An Enhanced DMAIC Method for Feature-Driven Continuous Quality Improvement for Multi-Stage Machining Processes in One-of-a-Kind and Small-Batch Production

This paper proposes an enhanced DMAIC (eDMAIC) method which succeeds from Six Sigma tool for the machining processes in multi-stage, small-batch or one-of-a-kind (M/S/O) production. As a modification and extension of the popular Six Sigma DMAIC, the eDMAIC method also consists of five phases, i.e., define, measure, analyze, improve, and control. Several specific tools in each phase are offered and how to use them is also interpreted. Then, a continuous quality improvement case is illustrated on how the eDMAIC method carries out in a machining workshop. It is proved that eDMAIC method contributes to a systematic solution when the machining processes are unstable. The eDMAIC method also offers an engineering approach to realizing better quality performances with lower cost in the context of M/S/O production with Six Sigma thinking.