I loved studying this stuff:
Toyota's "kaizen" system, developed more than 50 years ago after studying Ford's Rouge plant in Dearborn has helped it lead in quality for decades. This approach focuses on continuous improvement by avoiding repetition and waste while helping suppliers improve their own products, said Michael Flynn, director of the University of Michigan's Office for the Study of Automotive Transportation. U.S. automakers tend to seek quality improvements through new technology, he said.
Unlike Americans, the Japanese are very loyal to their suppliers.