Statistical Thinking, 3rd Edition

APPENDIX HDMAIC Process Improvement Framework

The significant problems we face cannot be

solved at the same level of thinking

we were at when we created them.

– Albert Einstein

In Chapter 5 we discussed frameworks for process improvement and problem-solving. (See Figures 5.7 and 5.14). These frameworks have been widely used for many years and are very effective. More recently the DMAIC framework has gained popularity (Snee and Hoerl 2018).¹ The DMAIC acronym stands for the five phases: Define, Measure, Analyze, Improve and Control. These phases are described and illustrated in this appendix.

The DMAIC framework came out of the Lean Six Sigma initiative, which is a statistically oriented business improvement initiative popularized by companies such as Motorola, General Electric, and Bank of America.² Key aspects of Lean Six Sigma include utilizing existing tools rather than trying to invent new tools, use of small project teams and project-by-project improvement approaches—both of which are supported by considerable research—and the use of existing tools that have solid theoretical bases, such as regression analysis and design of experiments.

Another key element of Lean Six Sigma is to have a common methodology, or framework, that is general enough to attack any problem within the “sweet spot” of Six Sigma. The DMAIC framework provides that common approach and is particularly effective for process improvement projects. We have found that it can be used successfully outside ...