Six Sigma vs. Lean Six Sigma

05/12/2007:

How does Six Sigma compare with Lean Six Sigma?
Kermit S., VP, Lean Initiatives


Nowadays, the terms Six Sigma and Lean Six Sigma are synonmous. A proper Six Sigma deployment includes use of the Lean tools and methods. Six Sigma is the umbrella deployment strategy for implementing value-added improvement projects aligned with the business needs of the organization. These focused projects target Critical to Quality (CTQ), Critical to Schedule (CTS) and/or Critical to Cost (CTC) opportunities (i.e. key Lean Six Sigma metrics) within an organization. Six Sigma uses a variety of tools and methods, including statistical (classical (enumerative) statistics, statistical process control, designed experiments), problem solving and consensus building, and lean tools. A given project may not use all of the tools, yet most organizations find they need most of the tools at any given time. Lean provides essential methods to define value and waste to improve the responsiveness to customer needs. As such, the Lean methods provide a critical means of accomplishing the Six Sigma goals, and is thus essential in every Six Sigma project. Similarly, the Lean methods require the use of data, and statistics provide the necessary methods for data analysis. It is unfortunate that some Lean advocates, and some Lean Six Sigma programs, do not stress the critical importance of the statistical tools in their analysis, since this lack of rigor will prevent projects from realizing their full potential, as the statistical tools (specifically SPC) provide the evidence of sustained process improvement for any key metric.

Learn more about the Lean Six Sigma principles and tools for process excellence in Six Sigma Demystified (2011, McGraw-Hill) by Paul Keller, in his online Lean Six Sigma DMAIC short course ($249), or his online Green Belt certification course ($499).