?? ?????? ?????? ????. ???????????? ?????????????????? ?????? ?????????????? ???????????? ?????????? ???????????????? ???????????????????? ?????? ?????? ????????????? It’s been thought that one reason Deming used standard deviations for charting his ?????? ???????? ???????????????????? results was to demonstrate how to analyze ???????????????????? ???????????????? data where material follows a simple pass/fail (binomial) distribution, ie. white==good, red==bad. ?? As it turns out, Deming didn’t know about alternative methods like the ?????? ?????????? (later known as the ?????????????? ?????????????????? ??????????) until 1985—when Dr. Donald Wheeler introduced him to it one evening over dinner ???. The Process Behavior Chart (PBC) as we know it today originated with the work of ??.??. ?????????????? at MO Valve Company, UK in 1942 and subsequently applied at GE Wembley between 1943-1953. Jennett had solved a problem that had stumped Deming’s mentor (and control chart inventor), Dr. Shewhart: creating a ?????????????? ?????????????????? for process control charts that could apply to ?????? ???????? ???? ????????, not just counts??. This technique, the ???????????? ??????????, or what Jennett called "?????? ???????????? ???? ???????????????????? ??????????????????????" forms the basis of the algorithm that my app, ?????? ???????????????? ??????, uses to reliably calculate process limits, either in their standard state (all data points), or when shifted/segmented. ?? Want to learn more? Dive into Dr. Wheeler’s insights in his paper here ?? The Chart for Individual Values: https://lnkd.in/g_AJ7ysN and check out the ???????? ?????????????? of my app that lets you explore your data using process behaviour charts, here: https://lnkd.in/gh8aN6qV
Bob Broach
3 周
Love this
Takt Times Group
3 周Your post does not answer the question about why 3σ limits. It’s a choice made by Shewhart, not Deming. According to Shewhart himself, the reason was that it was an accepted engineering practice. It was arbitrary. He explained it in his first book.