Process performance is universally described in practice by collecting data and calculating the mean (i.e. the mathematical average) performance. Unfortunately, the variation around the mean is almost never included when describing process performance. This is a critical oversight that is addressed by the Six Sigma methodology. Let me illustrate with an example that I often […]

On May 25th, 2014, **posted in:** Six Sigma by Roger EllisTags: Average, process performance, Six Sigma, variation

Most introductory courses in Six Sigma talk a lot about what Six Sigma is. In our Green Belt course I also include a discussion about what Six Sigma is not. I feel that this discussion is equally important when one is trying to understand the Six Sigma approach to problem solving and continuous improvement. The […]

In our Green Belt course I introduce the concepts of process capability and process control. I find that many students have trouble understanding the difference between the two. This is compounded by the fact that the output of a process may fall into of four possible combinations of capability and control. Process capability looks at […]

On April 14th, 2014, **posted in:** Six Sigma by Roger EllisTags: Process capability, Process control, Six Sigma

Most students of Six Sigma first become exposed to the concepts and ideas that drive the approach when they enroll in a Yellow Belt or Green Belt certification course. In both of these courses as offered by Key Performance, I included an early assignment with the title “What Is Six Sigma”? In this assignment I […]