What is Just-in-time (JIT)? | Objects and Benifits of JIT
Just-in-time (JIT) is a production model in which items are created to meet demand, not created in surplus or in advance of need. The purpose of JIT production is to avoid the waste associated with overproduction, waiting and excess inventory, three of the seven waste categories defined in the Toyota Production System (known in North America as the lean production model).
JIT was firstly developed within Toyota manufacturing plants by Taiichi Ohno, during the beginning of the 70s. The oil embargo probably triggered his theory, the program was intended to avoid wastes, reduce inventories and increase production efficiency in order to maintain Toyota’s competitive edge. Besides he believed that customers should be satisfied with maximum quality in the shortest time.
The JIT concept was described by Henry Ford in his 1923 book, My Life and Work:
We have found in buying materials that it is not worthwhile to buy for other than immediate needs. We buy 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 turnover and thus decrease the amount of money tied up in materials.
If we highlight JIT then….
- IT philosophy means getting the right quantity of goods at the right place and the right time.
- JIT exceeds the concept of inventory reduction.
- JIT is an all-encompassing philosophy found on eliminating waste.
- Waste is anything that does not add value.
A broad JIT view is one that encompasses the entire organization.
Objective of JIT:
- Produce only the products the customer wants.
- Produce products only at the rate that the customer wants them.
- Produce with perfect quality.
- Produce with minimum lead time.
- Produce products with only those features the customer wants.
- Produce with no waste of labor, material or equipment –every movement must have a purpose so that there is zero idle inventory.
- Produce with methods that allow for the development of people .
Benefits touted as results of JIT implementation include:
- Reductions in down time.
- Reductions in inventory.
- Reductions in scrap and re-work.
- Reductions in workspace.
- Increased inventory turns.
- Increased labor utilization.
- Increased equipment utilization.
- Improved service to customers.