Folks what is the difference between lean & six sigma? thanks

There is a discussion of the comparison here:
http://www.isixsigma.com/forum/showmessage.asp?messageID=16306

Here is a paper on the subject:
http://www.iee.org/oncomms/sector/management/Articles/Download/8616F1F6-032C-469A-9DD99660A0787832

Be well!

Also see: Lean-Six Sigma: What do critics say? (http://elsmar.com/Forums/showthread.php?threadid=11261)

I am asked that question frequently and always say that Six Sigma is fundamentally a step-by-step METHOD or PROCESS for solving a problem or making an improvement. Lean is a set of PRINCIPLES for maximizing the efficiency of a business or operation.

In each case there are a variety of TOOLS used, either to complete the Six Sigma process or improve based on a Lean principle. In many cases these tools overlap, which I think is what leads to all the confusion. For example, 5S implementation may be necessary for the Control phase of a Six Sigma project, and 5S is considered a fundamental tool of Lean.

"Six Sigma" and "Lean" are fundamentally different but complimentary. The Six Sigma PROCESS can be used to implement a Lean PRINCIPLE, for example reducing WIP inventory.

This debate has been going on for years. The isixsigma link provided by Jennifer is a good example. Also, because this is a SS forum, there is more pro SS than lean. I have spent a few months on this forum and found some excellent examples of SS tool applications as well as anal-retentiveness. The other link sent by Jennifer is a little better, but from my prespective, also a little one sided to SS thinking.

In a nut shell, SS works at reducing process variation. So, any process that is out of control needs first to be put in control before SS can work. This can be done with lean.

I believe the author of this other document link provided by Jennifer did not clearly understand that lean also meticulously uses strong statistical process control. As with SS, the target is a minimum of 1.33 Cpk. Where SS takes over is to improve the process capability even further.

So, what is the real difference.... from my perspective ... Six sigma ppl perfer to use SS principles, while Lean ppl perfers to use lean principles and 25% along the way, they both intersect in the usage of the same tools.

Here is one Presentation on Lean and six sigma


Sathis