Lean Production

It aims to combine the flexibility and quality of craftsmanship with the low costs of mass production .Lean production is the name given to a group of highly efficient manufacturing techniques developed (mainly by large Japanese companies) in the 1980s and early 1990s. Lean production was seen as the third step in an historical progression, which took industry from the age of the craftsman through the methods of mass production and into an era that combined the best of both. It has been described as “the most fundamental change to occur since mass production was brought to full development by Henry Ford early in the 20th century”.

The methods of lean production aim to combine the flexibility and quality of craftsmanship with the low costs of mass production. In lean-production systems a manufacturer’s employees are organised in teams. Within each team a worker is expected to be able to do all the tasks required of the team. These tasks are less narrowly specialised than those demanded of the worker in a mass-production system, and this variety enables the worker to escape from the soul-destroying repetition of the pure assembly line.
With lean production, components are delivered to each team’s work station just-in-time, and every worker is encouraged to stop production when a fault is discovered. This is a critical distinction from the classic assembly-line process, where stoppages are expensive and to be avoided at all costs. Faulty products are put to one side to be dealt with later, and a large stock of spares is kept on hand so faulty components can be replaced immediately without causing hold-ups. With such a system, workers on the assembly line learn nothing and the faults persist.
When a lean-production system is first introduced, stoppages generally increase while problems are ironed out. Gradually, however, there are fewer stoppages and fewer problems. In the end, a mature lean-production line stops much less frequently than a mature mass-production assembly line.
Lean production gains in another way too. In typical assembly-line operations, design is farmed out to specialist outsiders or to a separate team of insiders. Gaining feedback from both the production-line workers and the component suppliers is a long and awkward process. With lean production, designers work hand-in-hand with production workers and suppliers. There is a continuous two-way interchange. Snags can be ironed out immediately and machine tools adapted on the hoof. With the assembly-line model, the communication is linear.
Lean-production methods have been introduced by many companies without sacrificing economies of scale. Japanese car manufacturers have achieved unit costs of production well below those of more traditionally organised European and American manufacturers with twice their volume. These same Japanese companies have also been leaders in the speed and efficiency of new product design, a crucial skill in a world where time to market is an important competitive lever.
According to Michael Cusumano, who wrote a book on the Japanese car industry, the high productivity achieved by the lean-production methods of Japan’s car manufacturers depends not as some have maintained on a peculiarity of Japanese culture or of Japanese workers, but on technology and management. He wrote:
The methods challenged fundamental assumptions about mass production. These consisted of revisions in American and European equipment, production techniques, and labour and supplier policies introduced primarily in the 1950s and 1960s when total Japanese manufacturing volumes and volumes per model were extremely low by US or European standards.
Criticism of the idea has centred on the feeling that it is possible to be too lean. Beyond a certain point, a sort of corporate anorexia sets in. The total absence of surplus stock or labour can become a serious liability when there is even the slightest disturbance in normal processes or procedures.