Not long ago, in its global pursuit of the Truth, the Consultant Debunking Unit (CDU) journeyed to Japan for a tour of the car-making facility in Toyota City. Guided by engineers, we heard a lot about the legendary quality of Toyota's vehicles. Eager to show we knew a thing or two about quality ourselves, we soft-balled our hosts with the obvious question: "When did Toyota start using Six Sigma, anyway?"
Long silence. After some awkward consultation in Japanese, the engineers asked us, "What is Six Sigma?"
Good question. Sigma is the Greek symbol used to denote deviations from the mean. And so Six Sigma is essentially a set of procedures and tools designed to measure and analyze "defects" in a process and help determine what's causing them. The goal — the "six sigma" part — is 3.4 defects per million, or 99.997% perfection.
As with many management trends of recent vintage, blame Jack Welch for this one. The former General Electric CEO so believes in Six Sigma he devoted a chapter to it in Winning (HarperBusiness, 2005), writing, "You can't afford not to understand it."
Now, like a virtually flawless brushfire, it has spread well beyond its 1980s roots as a statistical tool for reducing manufacturing defects. Thousands of companies, from Sony to DuPont to Merrill Lynch, have flown in experts from the Six Sigma Academy and other consultancies to train cadres of so-called black- and green-belts in the ways of process control and deviation.
No one disputes the worthiness of Six Sigma's intentions, much less the statistics. But a quick survey of a handful of industries, using product-quality ratings from J.D. Power and Associates, led CDU to believe that while Welch may be right that you can't afford not to understand Six Sigma, you can't necessarily afford to use it, either.
In copiers and printers, Xerox ranks lower in quality than competitors Canon, Toshiba, and Hewlett-Packard, yet it proudly trumpets its Six Sigma legacy back to the 1980s. In wireless phones, quality varies by region, but Sprint PCS ranked highest only in the West; it tied in the Northeast with Verizon, which had "fewer problems experienced with static/interference." Nonetheless, quality consultancy Six Sigma Systems cites Sprint as a major client.
In boats (!), Larson Boats ranks last in a field of 11 companies that make express cruisers. It has two Six Sigma black belts on staff and boasts, "Quality isn't something we add at the end of the line!" And in cars, Ford stayed below average in the recent Initial Quality Study, despite its companywide policy in 1999 to adopt . . . well, you-know-what. Once again, the highest quality ranking went to Toyota — a company that had to learn about Six Sigma from the CDU.