ABSTRACT
The identifying and eliminating waste concepts of Lean and the identifying and eliminating variation concepts of DMAIC/DMADV have been difficult for the process improvement community to merge together in a seamless fashion, if at all. In fact, even today there remains poor understanding of how to make both of these excellent tools work in unison. Lean and DMAIC/DMADV show the individuality of each approach, and the complementary nature of these two unique and specific approaches together makes a powerful process improvement philosophy come alive. The goals of Lean can and do use some quantification; however, the Lean philosophy is predominantly qualitative in nature, and this overarching qualitative approach puts a few core beliefs above all activities. In fact, all activities should be traceable back to one of these qualitative business drivers. These are all activities driven by customer demand, establishing continuous flow of products or services to meet these customer needs, and driving waste out of the process until the customer receives perfection as a result of your efforts. The goals of DMAIC/DMADV are rooted in quantitative analysis and the scientific method. In their book Science for All Americans (Oxford Press, New York, 1990), Rutherford and Ahlgren note: “Scientific habits of mind can help people in every walk of life to deal with problems that often involve evidence, quantitative considerations, logical arguments, and uncertainty … involving four key values: curiosity, openness to new ideas, skepticism, and critical thinking. Curiosity means being filled with questions, seeking answers, and verifying how good the answers are. Openness means being discoveryoriented, even if the ideas are at odds to what is currently believed. Skepticism means accepting new ideas only when they are borne out by the evidence and logically consistent. Critical thinking means not being swayed by weak arguments. Collectively these 4 key values represent the foundation for Scientific Thinking.
