Largely considered a derivative from the Toyota Production System, lean manufacturing was originally developed as a remedy to diminish what are commonly referred to in Japan as ''the seven wastes'': defects, overproduction, transportation, waiting, inventory, motion, and overprocessing. These were first identified by Toyota’s chief engineer, Taiichi Ohno, who is widely considered the father of lean manufacturing. He famously penned several volumes on the concept, the most widely dispersed and read of which is Toyota Production System: Beyond Large-Scale Production. He also identified other wastes which should be limited or eliminated in the manufacturing process, including skill, safety, information, material, and breakdown.
Lean manufacturing is often implemented through two approaches. The first approach, known as Lean, deals primarily with the tools or equipment used to manufacture goods. The paramount concept of this method is to identify and implement tools which will reduce the amount of waste produced while simultaneously raising the quality of what is being manufactured in mass numbers. Continuous process improvement and mistake-proofing are key to this idea.
The second approach, known as TPS, spotlights something else altogether: making the work process as easy and seamless as possible. This method is heavily promoted by Toyota, which focuses much of its effort on what is known as ''production leveling,'' producing goods at a constant and predictable rate which keeps fluctuation of the rate of production at an absolute minimum.
TPS also includes two ''pillar'' concepts: JIT (flow) and autonomation (smart automation). Flow deals not only with the smoothness of the physical process of production but with regularly meeting customer demand for quality. If this can be satisfied, then improvement across all aspects of company production will result naturally. Autonomation, known informally as ''intelligent automation'' and ''automation with a human touch,'' refers to human intervention in the mechanical process of manufacturing wherein workers stop the production line in the event of an abnormality in production.
The four simple steps to successful autonomation are the following:
- Detect the abnormality.
- Fix or correct the immediate condition.
- Investigate the root cause and install a countermeasure.