View from the floor: Religion of Six Sigma

Religion has been a fundamental method of social and cultural organization ever since early hominids painted the walls of caves, but regardless of your opinion on Richard Dawkins or Christopher Hitchens, it’s a major influence on most of the world’s population.

Entire nations self-identify through faith and while there will always be a debate about “us-versus-them” among major religions, it’s interesting to think that manufacturing doesn’t actually have its own sect.

In the last 200 years, manufacturing has had at least as large an impact as religion on cultural and moral values and probably much more. The birth control pill and communications satellites come to mind immediately, but oddly there’s no religion based on the worship of technology. Instead, there’s an evangelical movement within the manufacturing community, whose religion is “Quality” and whose sects have titles like “Six Sigma”, “Lean” and “Zero Defects”.

Like God-based belief systems, these notions have evolved far from their original mathematical roots which were eventually expressed as statistical quality and process control. That’s amazing, considering that statistical methods have only been around part-making industries in a real sense for a little more than 70 years.

Christianity and Islam took centuries to go global, but visit any manufacturing plant on the planet and you’ll find a manager who’s aware of Six Sigma or Zero Defects. It really took off in the 1980’s, when hero CEOs like GE’s Jack Welch wrote books about management and preached the gospel of quality like the Sermon on the Mount.

And like real religion, that message has been distorted, usurped and appropriated to come to mean everything from a measure of variance from a statistical mean to a way to keep your management team motivated. Most of it, in my opinion, is useless.

The part that isn’t is the true core of statistical quality control and the tools we use to measure important attributes. There’s nothing “Lean” about standard deviation, but the amazing power of that bell curve to show us everything from the wear on a die to the assembler’s hangover is a real-world miracle that’s so buried in mathematics that we forget what it gave humanity.

Pre-statistical quality control products were, in a word, crap. Museums preserve the best of each age, but take a good look at an actual Model T Ford from the 1920’s and you’ll see an automobile that looks like it was assembled by drug addicts. It’s not that workers or engineers cared less; they simply didn’t understand what their micrometers and “go-no go” gauges were really telling them.

The breakthrough didn’t come from the high priests of industry like Henry Ford, it came from lay preachers like Shewart, Juran and Deming. William Edwards Deming in particular was ignored in his homeland and eventually banished to the manufacturing wilderness of Japan where he founded a true, science-based quality movement that eventually swept across the globe. Sound familiar?

An actual Model T Ford from the 1920’s is not of the best quality. It’s not that workers or engineers cared less; they simply didn’t understand quality in the sense we do today.

Deming’s “You Can’t Inspect Quality Into A Part”, is the mass-production equivalent to “Thou Shalt Not Kill”. While these men weren’t apostles in our sense of the word, in my opinion they put something more important into human culture than words on parchment.

Ask anyone who wears a pacemaker.