The paper proposes the misuse types of statistical quality tools according to the kind of data and the number of population in DMAIC process of six sigma. The result presented in this paper can be extended to the QC story 15 steps of QC circle. The study also provides the improvement methods about control chart, measurement system analysis, statistical difference, and practical equivalence.

Over ten years, 6sigma management is applied a lot in the part of indirect business as well as the manufacturing industry. But it has still been used restrictively the technique used on DMAIC that is a basic Roadmap of 6 sigma. This paper finds the improving skills that is used in the parts of manufacturing and indirect business and demonstrates their available scope with 6sigma projects. And this indicates which skills for improving are used valuable on each step of DMAIC with a systematic classification.

Over ten years, 6 sigma management is applied a lot in the part of indirect business as well as the manufacturing industry. But it has still been used restrictively the technique used on DMAIC that is a basic roadmap of 6 sigma. This paper finds the improving skills that is used in the parts of manufacturing and indirect business and demonstrates their available scope with 6 sigma projects. And this indicates which skills for improving are used valuable on each step of DMAIC with a systematic classification.