The Six Sigma Handbook, Revised and Expanded, 2nd Edition

20.8. SIX SIGMA AND LEAN

I am sometimes asked to explain the difference between Lean Production and Six Sigma. The question is usually phrased something like "Should I use Six Sigma or Lean Production methods to improve my operations?" Before I tell you my answer to this, let me summarize these two approaches to process improvement. Lean Production is based on the Toyota Production System (TPS). It usually includes the elements shown in Figure 20.6. When properly implemented, a Lean Production system can dramatically improve productivity compared with traditional batch-and-queue production systems, in some cases by 95%.

Ok, so how does this relate to Six Sigma? To make the comparison easier we need a new way of looking at "quality." I propose ...