Ever since Henry Ford invented the assembly line, industrial innovators have constantly focused on improvement through a variety of different manufacturing strategies. Lean manufacturing is a manufacturing strategy that seeks to produce a high level of throughput with a minimum of inventory.
Originally a Japanese methodology known as the Toyota Production System designed by Sakichi Toyoda, lean manufacturing centers around placing small stockpiles of inventory in strategic locations around the assembly line, instead of in centralized warehouses. These small stockpiles are known as kanban, and the use of the kanban significantly lowers waste and enhances productivity on the factory floor.
In addition to eliminating waste, lean manufacturing seeks to provide optimum quality by building in a method whereby each part is examined immediately after manufacture, and if there is a defect, the production line stops so that the problem can be detected at the earliest possible time. The lean method has much in common with the Total Quality Management (TQM) strategy. Both strategies empower workers on the assembly line, in the belief that those closest to production have the greatest knowledge of how the production system should work.
In a lean manufacturing system, suppliers deliver small lots on a daily basis, and machines are not necessarily run at full capacity. One of the primary focuses of lean systems is to eliminate waste; that is, anything that does not add value to the final product gets eliminated. In this respect, large inventories are seen as a type of waste that carries with it a high cost. A second major focus is to empower workers, and make production decisions at the lowest level possible.
Additionally, supply chain management factors heavily into lean manufacturing, and a tight partnership with suppliers is necessary; this facilitates the rapid flow of product and parts to the shop floor.
Lean manufacturing strategies can save millions of dollars and produce excellent results. Advantages include lower lead times, reduced set-up times, lower equipment expense, and of course, increased profits. It gives the manufacturer a competitive edge by reducing costs and increasing quality, and by allowing the manufacturer to be more responsive to customer demands.