Several years ago, the term Lean Six Sigma (LSS) appeared on the scene and since then, countless books, seminars, and conferences have popped up referencing the term. I’ve read books and articles on the subject but continue to have trouble understanding the distinction between LSS and just plain lean.
I’ve had people tell me that lean is about attacking waste; six sigma is about reducing variation; and LSS combines the two into a complete approach that is more effective than either by itself. Sorry, but this explanation still does not convince me that LSS adds anything besides confusion.
I have never seen an effective lean deployment – before or after the advent of LSS – that did not include a focus on reducing variation. Variation causes waste and interferes with flow and, because of this, must be addressed as a critical element to improvement efforts.
W. Edwards Deming wrote extensively about the importance of reducing variation, and Genichi Taguchi based his methods on minimizing variability. Both Deming and Taguchi heavily influenced Toyota and were integral to the development of TPS and lean.
If we want people to take lean seriously and truly buy into the approach, we have got to be consistent with the message. Rebranding lean and presenting it as something different risks turning it into just another business fad – which, for the sake of Western business, is something we cannot afford to let happen.