This methodology for improving manufacturing efficiency was taken by James Womack, copying the structure of the Toyota production system developed by Taiichi Ohno, director and consultant of the Toyota company "Toyota (company)"). Entered in 1937, Ohno observed that before the war, Japanese productivity was far inferior to that of the United States. After the war, Ohno visited the United States, where he studied the country's leading productivity and waste reduction pioneers such as Frederick Taylor and Henry Ford. Ohno was impressed by the excessive emphasis Americans placed on high-volume mass production to the detriment of variety, and the level of waste generated by industries in the richest postwar country. When he visited the supermarkets it had an immediate inspiring effect; Ohno found in them a perfect example of his idea of managing reduced inventories, eliminating unnecessary steps and controlling primary activities and giving control to the person doing the work (in this case the customer) as support to the value chain.[3] The Japanese word muda means 'waste' and refers specifically to any human activity that consumes resources and does not create value.
The term lean manufacturing came into use when the golden days of mass automobile manufacturing in the US ended in 1976 as a result of the bankruptcy of Chrysler and the money losses of GM and Ford. The second oil crisis also influenced this situation, which led automobile production in the United States to drop its production by 22%, and interest in Japanese manufacturing techniques. In particular, the Toyota production system, which led to the publication of two articles in 1977: one by Sugimori in the Journal of production research[4] and the other by Ashburn in the American Machinist.[5] These articles raised concerns in automotive companies in the United States and Europe. However, it was an NBC-TV broadcast by producer Claire Crawford-Mason in 1980, titled "If Japan Can, Why Can't We?" This sparked a quality revolution that led to the five-year, five-million-dollar IMVP research program.[6] This research later became known as JP Womack's research, which led him to publish the book "The Machine That Changed the World,"[7] where the term lean manufacturing appears for the first time.
The objective is to find tools that help eliminate all waste and all operations that do not add value to the product or processes, increasing the value of each activity carried out and eliminating what is not required. This manufacturing process is related to the use of activity-based costing (activity-based cost generation) which - according to its original version - seeks to relate costs with all the values that the customer perceives in the product. On the other hand, it serves to implement a philosophy of continuous improvement that allows companies to reduce their costs, improve processes and eliminate waste to increase customer satisfaction and maintain the profit margin. The purpose of lean manufacturing is to be useful to the community, which implies seeking continuous improvement.
Later approaches have managed to create derivations that are gaining popularity in the industrial world, developing tools such as Six Sigma, TPM, JIT and others that are implemented as part of lean manufacturing projects or even as individual tools. The most advanced organizations manage to have their own production systems, which are based on their own culture and idiosyncrasies. Examples of these are the monozukuri-based systems that are on the rise. They are based on step-by-step implementations according to the maturity of the organization, based on discipline and the formation of the base of the pyramid. Examples of these are the production system of the French automaker Renault and the Japanese automaker Nissan, which when they joined together came up with their own system that they called APW. Likewise, in other organizations they base the construction of their own system on generic systems such as monozukuri-genba, which includes lean manufacturing within its level 4 maturity.