The main idea of Lean Manufacturing is to increase the efficiency of a process by working smarter, not harder and without increasing the workload. This can be done by eliminating different kinds of wastes (non value adding process) as we will explain shortly.
This means that a production system produces and delivers the needed amount of products at the right time. When implemented correctly this will reduce overproduction and inventory and thereby the lead time. Also it provides possibilities to add flexibility in handling demand changes.
The elimination of errors is a very cost effective measurement. Faulty products are a source of waste, which sometimes can be overcome fairly easy. Processes can be designed with poka yokes (Japanese for “mistake proofing”). For instance parts should be designed in a way that they can only be installed by a worker in one possible way and thereby eliminating human errors.
With the introduction of standardized processes and operations we can eliminate variation in process times, operators can be trained easier and faults are found easier. This also provides a base for future improvements.
Kaizen means continuous improvement of a complete value stream or individual process by adding more value with less waste. This can be done by improving individual processes which can be done by every worker and improvement of the value stream, which is a task for the management. The improvement procedures are executed daily and “The idea is to nurture the company’s human resources as much as it is to praise and encourage participation in kaizen activities” (Tozawa, Bunji).
Off course these are just a few methods of lean manufacturing, but they will give a broad picture of what this field of expertise is all about.