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Quality Scan: Six Sigma: Point and Counterpoint






By H. Scott Tonk, CQIA
AEC, "The Quality Improvement Company"
Chicago, IL






Vivek Sharma, CMfgE, CQE
Senior Member, SME
Manufacturing Engineer
MC Assembly
Melbourne, FL


A recent Quality Scan generated considerable heat in the quality community. This exchange between the author and a reader encapsulates the debate.

To: Vivek Sharma:

Thank you for your very thoughtful editorial in the October 2003 issue of Manufacturing Engineering entitled, "Six Sigma: A Dissenting Opinion."

It's obviously better to shoot for zero defects (per the ZQC system pioneered by Shigeo Shingo) than to aim for 3.4 defects per million. No argument there. However, the question remains: How does one get to Zero Defects?

Nor can I argue with your thesis that Six Sigma has "not introduced even one original tool to the quality field." All the tools used by Six Sigma practitioners have been around for a long, long time, whether SPC or DOE or QFD or Pareto analysis or whatever.

But I think you miss the point of Six Sigma. Instead of these old quality tools being used in isolation, Six Sigma's approach is to integrate their application to solve problems in a coordinated way. In other words, Six Sigma uses these old quality improvement tools in a new way. That is where Six Sigma, as an approach to quality improvement, is original.

Allow me to use a military analogy. In World War I, infantry was used chiefly in mass assaults and trench warfare. Armor (tanks) was used chiefly as an infantry support arm. Artillery was used primarily for pre-assault barrages. And airplanes, which were in their infancy, were used chiefly for air combat, air reconnaissance, and a little (mostly ineffectual) bombing.

But then the Germans invented the Blitzkrieg. Its doctrine was to mechanize troops for rapid movement, to attack in mass armored formations, to use artillery to support these fast-moving assaults, and to use airplanes not only to blast the opposing air forces out of the sky, but to dive-bomb targets--applying each service arm in a coordinated, mutually supportive manner.

Six Sigma is the doctrine of blitzkrieg applied to quality improvement and problem-solving. That is its originality, and all of the case studies document its effectiveness. Personally I believe that no quality initiative is going to be truly effective unless it marshals all of the necessary and appropriate tools and applies them in a coordinated, integrated and mutually supportive manner--and in a routinely ongoing way.

Here are my disagreements with today's Six Sigma:

  • I don't think that the Black Belt version of Six Sigma is affordable by small to mid-size firms. Training Black Belts and Master Black Belts is far too expensive. Six Sigma is not for Fortune 500 firms only. Instead, we advocate the original Motorola version of Six Sigma (to which Motorola holds the trademark) called, "Six Steps to Six Sigma," which uses Green Belts instead of Black Belts. Green Belts can achieve 80% of the improvement. If a firm needs a Black Belt, it can hire an outside consultant.       
  • I disagree with the Six Sigma Orthodoxy that only certain quality improvement tools are appropriate Six Sigma tools. Use whatever quality improvement tools are appropriate for the project.

Six Sigma does indeed re-package the old tools. Brand marketing has indeed come to the quality profession. My only questions are these:

  • Which "brand" works better? The old, reliable brands alone or the brand that coordinates and applies the old brands in an integrated manner?
  • Do you want to fight a war using trenches and fixed fortifications, or would you rather go for a blitzkrieg?

H. Scott Tonk, CQIA


Mr. Tonk:

Thank you for taking the time to exhaustively respond to my Six Sigma Quality Scan.

Your Blitzkrieg analogy is refreshing, and I wish more people understood Six Sigma that way! But the message an average manufacturing engineer receives is that Six Sigma is a brand-new revolutionary tool. To judge from some of the mail I have received, that is what irks most engineers.

To add to your argument though, Six Sigma does focus on intensive financial tracking of projects, which has been the weak point of classical engineers. Maybe that explains its popularity with managers!

Vivek Sharma, CMfgE, CQE


This article was first published in the January 2004 edition of Manufacturing Engineering magazine. 

Published Date : 1/1/2004

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