TCS: Your research on lean management practices dates back more than 30 years. Can you tell us about the genesis of lean thinking? Michael Cusumano: As part of my doctoral thesis on the Japanese automobile industry, and eventually for a book I published (The Japanese Automobile Industry: Technology and Management at Nissan and Tokyo, Harvard University Press, 1985), I analyzed the Toyota production system in the 1980s. I studied their productivity at the company level—units [outputs] per company as well as value-added—and I adjusted for things such as labor hours, capital investment, and capacity utilization. Toyota was producing vehicles with half the number of people [used by the American companies], but with the same amount of capital equipment. That was interesting. So what was ‘lean’ at that time was the number of people. Then, a student of mine—John Krafcik, who was working on his master’s thesis here at the MIT Sloan School— studied the Japanese production system at a more abstract level. John took this thinking to the assembly plant level: What was productivity like there? What degree of automation did they have in the assembly plants? What management practices did they use?