This article has a few problems — including lumping in Lean as “quality control” system — but points to how Six Sigma went from business process engineering star to being out of fashion. The problem wasn’t (isn’t) with Six Sigma, its in its application (and the huge array of management consultants proffering it for everything and anything). Its good for process efficiency (particularly in manufacturing defect control where it originates from) but not applied to every process in a company especially those relating to technology.

It reminds me of this diagram which I use in my teaching and thing about often:

This is not to say efficiency be dammed but that efficiency is the goal of operationally focused people and teams in mature processes. Its not the goal of technology, innovation, new product development and other areas where you need to leap.

According to Google, searches for “Six Sigma” peaked in 2004, and have fallen steadily since. LinkedIn data reveal a similar story, with fewer and fewer of its 630 million users adding Six Sigma as a skill to their online résumés. It’s since been surpassed by Agile, a management process that emerged from the world of software development.

https://qz.com/work/1635960/whatever-happened-to-six-sigma/