This article begins with a quote from Deming in the New Economics: “Conformance to specifications, zero defects, Six Sigma Quality, and all other (specification-based) nostrums all miss the point.”
In addition a good history of the Crosby contributions to Zero Defects and quotes from Dr. Juran on Six Sigma are included. The paper finishes with the Taguchi Loss Function and Deming's System of Profound Knowledge.
Lost to history is the experience of Ford with the Batavia Plant where they were making exactly the same transmission as Mazda. This provides a real life example of the difference focusing on meeting specification versus manufacturing to target (Taguchi's idea). Both outputs from Mazda and Ford were within specification. However, the Ford transmissions had twice the customer problems as the Mazda transmissions. VP John Beti famously remarked, "While we were busy meeting specifications, they were busy making them all the same." If you have never seen this video produced by Ford, it is worth the time. It is less than 12 minutes long.
Ford at first elected to close the Batavia plant. This caused an outbreak of cooperation between the management and the union. It took the plant 8 months to match the quality of Mazda.
Harry Truman once remarked, "History does not repeat itself. We just keep making the same stupid mistakes."
Deming warned us in 1993 before he passed: : “Conformance to specifications, zero defects, Six Sigma Quality, and all other (specification-based) nostrums all miss the point.” Since his passing we now have a world wide movement that is back to focusing on specifications.
