Lean manufacturing

Several of the comments on Six Sigma R.I.P.   touched on certification. With the belt system, this issue is of course central to Six Sigma, and, with Six Sigma on the Lean bandwagon, is merging with that of Lean certification, as evidenced in plant Lean champions who introduce themselves as Black Belts.

In his comment, R. Kester said the following:

Certification is the accepted way to communicate to others that you have successfully studied and can apply the concepts and tools of your profession (CPA, MD, RN, PE, etc.).

It is true that you want a Certified Public Accountant to help with your taxes, and that, if you go to a clinic, you don’t want anyone to mess with your health who doesn’t have the proper credentials posted on the wall. On the other hand, if you buy a painting, you usually don’t care whether the artist learned the craft in a school of fine arts or by spraying city walls: the paintings tell you all you need to know. There are also fields where certification exists but is not necessarily sought by all. For example, many university engineering departments seek ABET (Accreditation Board for Engineering and Technology) certification, but some don’t, such as Electrical Engineering at MIT, UC Berkeley, or Stanford. Their own brands are more prestigious and better known than ABET.

In the continuum of certifiable human activities, where does Lean sit between MDs and CPAs on one side and artists on the other? Lean experts sell their services to businesses, not consumers, and the primary use of certification is as a job applicant filter. To a recruiter with no personal knowledge of Lean and 100 resumes to review, the absence of a Lean certification is quick way to dispose of 80%. But what guarantee does the Lean certification give  that the surviving 20% are the best candidates?

For a certification process to achieve this result, there has to be a consensus on a body of knowledge (BOK) and on institutions qualified to certify proficiency in its application. Having doubled life expectancy in 200 years, modern medicine is a credible BOK. We know its theories are sound because they prevent, cure or control many diseases. Tax law is different, in that it is a set of rules defined by people for people to follow, like the rules of poker.  Outside of a specific human society, there is no corresponding physical reality. The difference between the two was dramatized in the library scene in  The Day After Tomorrow: the coming of a new ice age had made the tax code fit for burning, but medicine had retained its relevance, as seen when the heroes used a medical book to save one their own (See Figure 1.).

Figure 1. Burning the tax code to survive in a new ice age

In that it affects the physical reality of factories, Lean is more like medicine than tax law. However, besides the absence of consensus on a  BOK, Lean manufacturing differs from medicine is in the role of institutions, and academia in particular. Most medical discoveries are made in university medical schools; nearly all breakthroughs in manufacturing, on the other hand, have been made by self-taught practitioners in factories, with no academic affiliation. I am thinking of high school graduates like Taiichi Ohno, Frank Gilbreth, Charles Sorensen, or Frederick Taylor. Whatever consensus eventually emerges on a Lean BOK, it will not have come from universities. This leaves professional societies and for-profit training companies, and no answer to the question of who certifies the certifiers.

By requiring certifications, company recruiters are making them valuable to applicants, and are generating business both for genuine training organizations and for diploma mills. However, what these recruiters are not doing is their job, because  the next Taiichi Ohno won’t make it past their initial review.