A Comparison of Six Sigma to Lean Manufacturing, Strategic Quality Management, and
There are a plethora of management strategies and perspectives that are being employed in operations and supply chain management in the modern business environment. Among the various theories being implemented, Six Sigma, Lean Manufacturing, Strategic Quality Management, and Total Quality Management are among the most popular. This paper will compare and contrast some of the different points associated with these models to provide an introduction into the different strategies as well as look at some of the research that has been conducted in these areas.
Six Sigma, Lean Manufacturing, Strategic Quality Management and Total Quality Management Discussion
Six Sigma has gained a significant amount of attention in industry however comparatively little research has been conducted on the conceptual definition and underlying theory associated with this model (Schroeder, Linderman, Liedtke, & Choo, 2008). In fact, in the beginning of Six Sigma’s development, many business professional felt that it was just another fad that was that was built upon a model that was basically Total Quality Management (Basu & Wright, 2012). Even hybrid models were developed that mixed Six Sigma with other models such as FIT Sigma which incorporated Lean Manufacturing ideas into it. However, today Six Sigma has stood the proverbial test of time and is a theory that has stood on its own two feet.
The central idea to the Six Sigma model is that statistical modeling of production processes can help reduce defects down to the sixth sigma in a normal distribution model; or three point four defects per one . This is a rather aggressive feat that from the organization to constantly work to improve quality. Though this is similar to the approach used in Total Quality Management, there are major differences between the two theories. For example, the Six Sigma approach is heavily dependent upon structure and statistical analysis to drive quality improvements while TQM is more focus on teamwork and the underlying philosophy of quality management. Yet the two theories are still similar enough that researchers have been studying the organizational cultures involved with both models to try to tease out the subtleties involved with each.
Figure 1 – Example of Organizational Culture Research Examining TQM/Six Sigma (Zu, Robbins, & Fredendall, 2010)
Lean Manufacturing by contrast to Six Sigma, is more of a philosophy than a structured approach to improving defect rates. Lean Manufacturing replaced the (JIT) manufacturing fad that focused on decreasing inventories and the risk of obsolescence. In fact, the concepts of JIT and TQM mirror those of Lean Manufacturing and Six Sigma that some researchers have actually applied the product lifecycle model to the trend in management models. Research has indicated that Lean Manufacturing and Six Sigma are repackaged versions of their former models and given that they are ending their lifecycles, it is estimated that new management trends are expected to emerge shortly (Naslund, 2008).
However likely that is to be the case, Lean Manufacturing is an approach that focuses primarily on reducing waste. Anything that does not add value to the consumer or the finished product is considered to be waste. Therefore things like inventory and administrative functions are waste. Inventory does not add value to the end product or to the customer because it adds nothing significant tot the product. It is more of a necessary evil that results from inefficient systems and the same can be said about administration.
Strategic Quality Management and Total Quality Management are also closely related concepts. Strategic Quality Management is a more focused version of the later in which a structured approach to quality management is gear toward the critical process of a company (Vinzant & Vinzant, 1996). However, the history of Total Quality Management, as well as the roots of the new models can be traced back to Deming’s 14 points which developed in the 1950’s by W. Edwards Deming. Deming is most known for his work in Japan through his lectures which help the Japanese build their quality control (Deming, 2011). Using these concepts, the Japanese production increased and their quality of in relation to production in other parts of the world.
Deming has such an effect on production in Japan that it helped the country improve its entire economy. In the United States the majority of the professionals rejected Deming’s ideas until they were put into practice overseas and started showing results. It wasn’t until the 1980’s that the United States started to see what an impact Deming had made on Japan and then they started to look at Deming’s 14 principles. Companies like Ford, General Motors, and Florida Power & Light consulted with Deming because their production capacities palled in comparison to the one’s that took Deming’s work seriously.
All of the models that that are being used today can be traced back to Deming’s work on Total Quality Management. Although there are many differences in the models, at the core of these concepts is an approach to improve quality and efficiency. Although it has been identified that some professionals believe all the different models to be nothing more than a fad, the improvements gained by implementing different quality initiatives are real. It is likely that the business world will experience a new generation of management models that are based upon Six Sigma and Lean Manufacturing as these had their roots built upon TQM and JIT.
Basu, R., & Wright, N. (2012). Quality Beyond Six Sigma. New York: Routledge.
Deming, W. (2011, September 22). The Deming System of Profound Knowledge. Retrieved from The W. Edwards Deming Institute: http://deming.org/index.cfm?content=66
Naslund, D. (2008). Lean, six sigma and lean sigma: rads or real process improvement methods? Business Process Management Journal, 269-287.
Schroeder, R., Linderman, K., Liedtke, C., & Choo, A. (2008). SixSigma: Definition and underlying theory. Journal of Operations Management, 536-554.
Vinzant, J., & Vinzant, D. (1996). Strategic Management and Total Quality Management: Challenges and Choices. Public Administration Quarterly, 201-221.
Zu, X., Robbins, T., & Fredendall, L. (2010). Mapping the critical links between organizational culture and TQM/SixSigma practices. International Journal of Production Economics, 86-106.