L EAN M ANUFACTURING

(Arthur Gill, Consultant – Kelmar Associates)

Lean Manufacturing is a philosophy of manufacturing that can trace its origins as far back as the emergence of the Japanese auto industry in the 1960s. It involves a wide variety of manufacturing techniques such as Value Stream Mapping, Pull Systems, and Cellular Manufacturing that are meant to improve overall production efficiency. Today, there are few companies that are not either actively involved in or considering the implementation of some kind of lean philosophy in their day-to-day operation. Figure 10-2-1 compares the requirements for mass production and lean manufacturing.

Fig. 10-2-1 A comparison of the requirements for mass production and lean manufacturing. (Advanced Manufacturing)

THE TOYOTA PRODUCTION SYSTEM

The Toyota Production System (TPS), developed during the 1950s and 1960s, is generally acknowledged to be the first example of a company that included lean principles in a consistent and understandable system of production. After studying the Rouge auto complex at Ford in Detroit for a number of months, Eiji Toyoda and his colleagues realized that the American mass production system would not work in Japan for a variety of reasons. The main reason was the significant difference in the customer base of the two countries. The Japanese market simply could not support the large lot sizes that the American mass production system was built on. Instead, the Japanese adopted an approach similar to U.S. supermarkets at that time, where small quantities of every product were placed on shelves and quickly refilled when necessary. This concept was introduced into auto production where inventory supermarkets were placed throughout the plant. This resulted in a significant lowering of waste in on-site inventory. Figure 10-2-2 provides a more detailed overview of mass versus lean production methods.

Fig. 10-2-2 A detailed overview of mass versus lean production methods. (Advanced Manufacturing)

The basic goal of the Toyota Production System is to create a manufacturing environment in which more is done with less time and effort. This includes reducing the amount of resources, inventory, and time involved in the manufacturing prowess. Equally important to the success of the TPS and all lean endeavors is the role of workers. Their input, creative ideas, and problem solving is encouraged and rewarded. Like any major change in an organization, the workforce has to be actively consulted and included on the team if there is to be a truly successful change from the old to the new.

The incredible rise to prominence of the Japanese auto industry in a relatively short period of time is evidence of the success that this philosophy of manufacturing created.