Lean six sigma

Lean
Lean Six Sigma

Michael L. George

This booklet contains a preview of Section I of Lean Six Sigma. It is printed with permission from McGraw-Hill. The full version of the book will be published in Spring 2002.

Preface
In 1996, General Electric CEO Jack Welch praised Six Sigma as “the most important initiative GE has ever undertaken.” Yet despite widespread success with Six Sigma, two years later Welch articulated one shortfall:
“We have tended to use all our energy and Six Sigma science to move the mean [delivery time] to… 12 days. The problem is, as has been said, ‘the mean never happens,’ and the customer is still seeing variances in when the deliveries actually occur—a heroic 4-day delivery time on one order, with an awful 20-day delay on another, and no real consistency… variation is evil.”
Welch’s statement was prompted by a growing awareness that time is nearly as important an improvement metric as is quality—and that reducing process lead times and variation in the amount of time it takes to complete a process has just as much potential for improving a company’s performance as does reducing variation in quality.
Sometimes we regard our customers are like the man who has one foot in the fire and the other in a block of ice: On average, he should be comfortable! But obviously the range of temperatures is intolerable— just as unpredictable delivery time is to our customers.
Most of the methods and tools associated with Six Sigma do not focus on time; they are concerned with identifying and eliminating defects.
Any savings in time that result from Six Sigma projects are often a byproduct of defect reduction and of the general problem solving methodology. That’s why in GE’s 2000 Annual Report (dated February
2001), Jack Welch announced a additional goal for GE: reducing the variation in lead-time (which he refers to as “span”):
“Today we have a Company doing its very best to fix its face on customers by focusing Six