After World War II, Japanese industrialists visited the United States to know their quick weapons production for the war and specifically they studied production methods of Henry Ford, Ishikawa, Edwards Deming, and Joseph Juran.
During 1949 and 1975, in Toyota Motor Company, Taichii Ohno and Shigeo Shingo, began to incorporate Ford production and other techniques into an approach called Toyota Production System or Just In Time. But, they found flaws in the Ford system, especially with treatment towards employees as Ford used employees only for muscle power.
Toyota found that employees can contribute more than just muscle power and which led to Quality Circle movement (Quality Circles were groups of workers who met together regularly to discuss how to be more “LEAN”.)
Though Ford system focused on a single, never changing product, the Toyota Production System involved product variety by reducing setups to minutes and seconds which allowed small batches or different variations in products. The new system spread to other Japanese companies who made gains in productivity and quality after which, American executives traveled to Japan to study it.
The Toyota Production System (TPS) focuses on muri and muda. Muri focuses on the preparation and planning of the process, or what work can be eliminated in the design process. Muda are those waste steps and processes that add cost. Muri is used in new product design and muda is used to improve existing operations.
