In today’s competitive world shorter product life cycles, customers rapid demands and quickly changing business environment is putting lot of pressures on manufacturers for quicker response and shorter cycle times. Now the manufacturers put pressures on their suppliers. One way to ensure quick turnaround is by holding inventory, but inventory costs can easily become prohibitive. A wiser approach is to make your production agile, able to adapt to changing customer demands. This can only be done by JUST IN TIME (JIT) philosophy. JIT is both a philosophy and collection of management methods and techniques used to eliminate waste (particularly inventory). Waste results from any activity that adds cost without adding value, such as moving and storing. Just-in-time (JIT) is a management philosophy that strives to eliminate sources of such manufacturing waste by producing the right part in the right place at the right time.
JIT (also known as lean production or stockless production) should improve profits and return on investment by reducing inventory levels (increasing the inventory turnover rate), reducing variability, improving product quality, reducing production and delivery lead times, and reducing other costs (such as those associated with machine setup and equipment breakdown). The basic elements of JIT manufacturing are people involvement, plants, and system. People involvement deal with maintaining a good support and agreement with the people involved in the production. This is not only to reduce the time and effort of implementation of JIT, but also to minimize the chance of creating implementation problems. The plant itself also has certain requirements that are needed to implement the JIT, and those are plant layout, demand pull production, Kanban, self-inspection, and continuous improvement. The plant layout mainly focuses on maximizing working flexibility. It requires the use of multi-function workers”. Demand pull production is where you produce when the order is received. This allows for better management of quantity and time more appropriately. Kanban is a Japanese term for card or tag. This is where special inventory and process information are written on the card. This helps in tying and linking the process more efficiently. Self-inspection is where the workers on the line inspect products as they move along, this helps in catching mistakes immediately. Lastly continuous improvement which is the most important concept of the JIT system. This simply asks the organization to improve its productivity, service, operation, and customer service in an on-going basis.
In a JIT system, underutilized (excess) capacity is used instead of buffer inventories to hedge against problems that may arise. The target of JIT is to speed up customer response while minimizing inventories at the same time. Inventories help to response quickly to changing customer demands, but inevitably cost money and increase the needed working capital. 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-vPolume repetitive flow manufacturing processes.
The technique was first used by the Ford Motor Company as described explicitly by Henry Ford’s My Life and Work (1922): “We have found in buying materials that it is not worth while to buy for other than immediate needs.” They bought only enough to fit into the plan of production, taking into consideration the state of transportation at the time. If transportation were perfect and an even flow of materials could be assured, it would not be necessary to carry any stock whatsoever. The carloads of raw materials would arrive on schedule and in the planned order and amounts, and go from the railway cars into production. That would save a great deal of money, for it would give a very rapid...