Les,
Hi! Thank you for your comment/reaction to my post.
The word "sigma" cannot be claimed by mathematics or statistics as its own original invention. In fact, it is mathematics and statistics that borrowed the lowercase (small letter) of the 18th letter of the Greek alphabet and used it as a symbol for standard deviation.
If you look at linguistic history, you will realize that the word "sigma" was derived from the Phoenician alphabet called "sin", although it is alleged to have actually originated from "samekh". The word "sigma" in Greek numerals connotes a specific value of 200 and not probabilities of the number of defects per process.
In today's science and math, the word sigma is being used in many ways, e.g. sigma bonds in chemistry, sigma algebras, sign of division function in number theory, sigma factor of RNA, used as a symbol of electrical conductivity, symbol of normal stress in continuum mechanics, etc.
Six Sigma is now understood worldwide as a quality improvement tool. However, it did not exist in the early 1980s when great minds like Deming, Juran, etc. were already implementing quality improvement tools worldwide.
The Six Sigma concept started at Motorola (not GE as some claim) in 1987 when the company embarked on a "process improvement methodology" to counteract the emerging Japanese manufacturing concepts that were threatening even the memory chip market in 1985-1986.
According to Alan Ramias of PDLab, Six Sigma is simply "a repackaging of tools and techniques already in place". Hence, the achievements at Motorola in 1988 that gave them the first Malcolm Baldrige Quality Award (in 1988) were not primarily due to Six Sigma, but "were a result of all TQM and BPI efforts". According to A. Ramias, there was "no such thing as a single comprehensive program called Six Sigma" during that time. By the way, A. Ramias claims to be part of the original team that developed the Six Sigma concepts together with Geary Rummler.
Moreover, if you look at Six Sigma's two main methodologies today (DMAIC & DMADV), they are not far from the Japanese TQM concepts that include the concepts Kaizen and Five "S". This is the reason why I raised that point in my earlier post.
To intrigue you more, I challenge you to look at today's CMMI concept in the software industry that is being popularized by the Software Engineering Institute of Carnegie Mellon University. Try to examine CMMI and compare it with the "ISO QMS" and Six Sigma methodologies. Can you see similarities?
Or, why don't you compare ERP (Enterprise Resource Planning) with the Japanese concepts Kanban and JIT (Just-in-Time) inventory management system popularized by my previous employer Toyota?
I hope this clarification and exchange of ideas will help people grow professionally and intellectually. Indeed, when it comes to knowledge, many of us will do well if we use some historical analysis in understanding things in this world.
And many of us will do well if we avoid being "copycats" regardless of where we are on this planet.
Best wishes.
Ed Llarena, Jr. Managing Partner Emilla Consulting