Lean Six Sigma

Sarah Foster

Blog Post #2 – Connection to Week 3: Lean Manufacturing, TQM, and Operational Improvement

Six Sigma vs. Lean Six Sigma

I always hear Six Sigma mentioned in classroom and business settings, and I have even sat in on a Six Sigma problem-solving meeting during an internship a couple of years ago.  However, I never really knew the exact definition and description of Six Sigma.  In Managing Quality with Process Control, Six Sigma is defined as “a managerial approach, which uses a variety of statistical and problem-solving tools to solve process problems and reduce defects.”[1]  Six Sigma sets strict defect targets, and it strives to discover how an organization achieves this high level of quality by “identifying and removing the causes of defect and by minimizing variability.”[2]

I wanted to delve further into Six Sigma because I like that it is based on data-driven problem solving. I came across an article that I found interesting because it introduced me to the term “Lean Six Sigma,” which I had never heard before:

“Six Sigma vs. Lean Six Sigma,” University Alliance, Villanova University, Accessed September 7, 2014, http://www.villanovau.com/resources/six-sigma/six-sigma-vs-lean-six-sigma/#.VA1hL_ldVlp.

The article first compared Six Sigma with Lean manufacturing.  The goal of Six Sigma is the elimination of defects, whereas “the main emphasis of Lean is on cutting out unnecessary and wasteful steps in the creation of a product so that only steps that directly add value to the product are taken.”[3]  The article claims that the end goal of both approaches is basically the same, “eliminate waste and create the most efficient system possible;” the difference is how the root cause of waste is identified (waste due to unnecessary steps versus waste due to variation).[4]

The article goes on to offer a panacea to the dilemma over which approach an organization should take – use a combination of the two, Lean Six Sigma.  This is a relatively new concept, but in my opinion just a new neologism that will be marketed by companies who will offer Lean Six Sigma certification and training.  It seems like anyone truly knowledgeable and experienced in operations would already be incorporating best practices from a variety of approaches.  However, in the article Decoding the DNA of the Toyota Production System, Toyota’s Lean approach is discussed, and authors attribute the car manufacturer’s success to its “four unwritten rules” that “govern how people carry out their jobs, how they interact with each other, how products and services flow, and how people identify and address process problems.”[5]  

•          Do you think companies like Toyota that already has such an efficient Lean-based operations system would benefit from incorporating Six Sigma/Lean Six Sigma?  Or would that interfere with its utilization of its four governing rules?

•          What about companies that haven’t achieved Toyota’s efficiency? Would they benefit from a Lean Six Sigma approach more so than either a Lean approach or a Six Sigma approach?

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[1] Roy D. Shapiro, “Managing Quality with Process Control,” Operations Management Core Curriculum, Harvard Business School, September 12, 2013.

[2] Ibid.

[3]  “Six Sigma vs. Lean Six Sigma,” University Alliance, Villanova University, Accessed September 7, 2014, http://www.villanovau.com/resources/six-sigma/six-sigma-vs-lean-six-sigma/#.VA1hL_ldVlp.

[4] Ibid.

[5] Steven spear and H. Kent Bowen, “Decoding the DNA of the Toyota Production System,” Harvard Business Review, 2006.