Jim’s comment in the last post on “Lean Certification” rhetorically asks “…why are there Six Sigma Black Belts?”
Interesting question. It brings up one of the very fundamental differences between the Toyota Production System and a couple of other popular disciplines, notably Six Sigma and Theory of Constraints. Both of these other disciplines have certified practitioners.
Six Sigma certifies “Black Belts” plus five other flavors under a program defined by the ASQ.
Theory of Constraints has “Jonahs” which are certified by the Goldratt Institute.
I am emphatically not going to get into a discussion about the relative merits of these systems. They are all based on the same fundamental principles, and will all deliver exactly the same results if they are applied consistently and universally. Many of the debates come from people trying to compare sub-sets of understanding. Many of those debates are fueled by the fact that people have considerable time and possibly money invested in “the way.”
But one key difference between the Toyota Production System and the other two is the origin of knowledge about them.
Theory of Constraints was deliberately designed.
Six Sigma was deliberately designed.
The Toyota Production System organically evolved.
That is not to say that TOC and Six Sigma are not evolving. They must evolve if they are to deal with problems that were not anticipated by their original designs. But those seeking to understand them go to the official repository, and learn the official, latest, version. There is a definition of “complete knowledge.”
Contrast this with Toyota’s system. It was not deliberately designed, it evolved. Certainly there are people with very deep understanding, and certainly if you visit a Toyota operation there is a system in place.
However those seeking to understand it must learn by study and research. Academics study Toyota and application of their system, trying to figure out how and why it works. They ask questions like “What is different about Toyota’s application and everyone else’s?”
In order to answer those questions they must make observations, develop hypotheses, make predictions and test them.
As a result, our understanding of why the Toyota Production System performs as it does has evolved over the years. There is no standard for complete understanding, there is only “keeping up in your field.”