Definition Lean Production. Description.
Lean Production is a manufacturing performance improvement approach and philosophy that emphasizes the minimization of the amount of all the resources (including time) used in the various activities of the enterprise. It involves identifying and eliminating non-value-adding activities in design, production, supply chain management, and dealing with the customers.
Lean producers employ teams of multi-skilled workers at all levels of the organization and use highly flexible, increasingly automated machines to produce volumes of products in potentially enormous variety. It contains a set of principles and practices to reduce cost through the relentless removal of Waste and through the simplification of all manufacturing and support processes.
What is Just-in-Time? Definition
Just-in-time was pioneered by Taiichi Ohno in Japan at the Toyota car assembly plants in the early 1970s. It is a manufacturing organization philosophy. JIT decreases waste by supplying parts only when the assembly process requires them. At the heart of JIT lies the kanban, the Japanese word for card. This kanban card is sent to the warehouse to request a standard quantity of parts as and when they have been used up in the assembly/manufacturing process. JIT requires precision, as the right parts must arrive "just-in-time" at the right position (work station at the assembly line). It is used primarily for high-volume repetitive flow manufacturing processes.
History of Just-in-Time
Historically, the JIT philosophy arose out of two other things:
1. Japan's wish to improve its production quality. At that time, Japanese companies had a bad reputation as far as quality of manufacturing and car manufacturing in particular was concerned.
2. Kaizen, also a Japanese method of continuous improvement.
The Just-in-time framework regards inventories as a poor excuse for bad planning, inflexibility, wrong machinery, quality problems, etc. The target of JIT is to speed up customer response while minimizing inventories at the same time. Inventories help to respond quickly to changing customer demands, but inevitably cost money and increase the needed working capital.
In 1990 James Womack wrote a book called "The Machine That Changed The World", introducing the terminology 'Lean Manufacturing'. Also you may encounter the word: 'Lean Production'. The principles behind these approaches do not substantially differ from the techniques developed by Ohno at Toyota.
Attention Areas of Just-in-Time
Typical attention areas of JIT implementations include:
* Inventory reduction.
* Smaller production lots and batch sizes.
* Quality control.
* Complexity reduction and transparency.
* Flat organization structure and delegation.
* Waste minimization.
External extended Just-in-Time
Through the arrival of Internet and Supply Chain Planning software, companies have in the mean time extended Just-in-time manufacturing to outside the company borders. By demanding from their suppliers to deliver inventory to the factory only when it's needed for assembly, making JIT manufacturing, ordering and delivery processes even speedier, more flexible and more efficient. In this way, Integrated Supply Networks (Demand Networks) or Electronic Supply Chains are being formed.
موضوع مطلب : تئوریهای مدیریت