From Supply Chain Management Encyclopedia
"Just-in-Time" or JIT means making "only what is needed, when it is needed, and in the amount needed." JIT is also known as lean production or stockless production, which reduces inventory in a firm. But still there is a difference between the concepts of JIT which is a philosophy and the Quality control Management which is a practice. Just-In-time is a management philosophy aimed at eliminating manufacturing wastes by producing only the right amount and combination of parts at the right place at the right time . Eliminating wastes statement is based on the fact that wastes result from any activity that adds cost without adding value to the product, such as transferring of inventories from one place to another or even the mere act of storing them.  JIT dates back to the early 1970’s when it first appeared in Japan, after being developed and perfected by Taiichi Ohno of Toyota Company. Taiichi Ohno developed this philosophy as a means of meeting customer demands while minimizing delays. Thus, in the early days, JIT was used not to reduce manufacturing wastage, but primarily to produce goods so that customer orders were met exactly when they needed the products.
Objectives of JIT
There are three main objectives of JIT system, could be emphasized among the others :
- Increasing the organization’s ability to compete with others emphasizing the long run period. JIT manufacturing process is a more optimal process for the firm, what helps to increase the competitiveness.
- Increasing efficiency within the production process. Efficiency is obtained through the increase of productivity and decrease of cost.
- Reducing wasted materials, time and effort, which lead to the costs reduction.
Elements of JIT
According to R. Dan Reid & Nada R. Sanders  the are the following elements of JIT system:
- Value-added manufacturing
- Inventory reduction - exposes problems
- Kanbans & pull production systems
- Small lots & quick setups
- Uniform plant loading
- Flexible resources
- Efficient facility layouts
- Total Quality Management which is an integrated effort designed to improve quality performance at every level
- Human resources as respect for people rests on the philosophy of JIT
Benefits of JIT
Advantages of working in JIT system could be grouped the following way:
- Product costs are greatly reduced of manufacturing cycle time, reduction of scraps, inventories, space requirements, material handling and eliminations of non-value adding operations
- Quality is substantially improved due to fast detection and correction of defects, use of automatic stop devices, higher quality of purchased parts, worker centered quality control and statistical process control. Total preventive maintenance and lower inventory levels also help in quality improvements.
- Design. Due to the reduction of set-up times (changeovers), alternative designs can be quickly brought on the shop floor.
- Productivity. Order level productivity improvements are obtained due to the use of flexible workforce, reduced rework, reduced inspection, reduced part delay and reduced throughout time and manufacturing lead time. Workers acquire multiple skills and become highly productive, they participate in problem-solving.
Expressed in numbers an empiric analysis in JIT production and delivery in 172 European companies has shown that by the introduction of JIT production a reduction of the door to door time by 60-90%, a decrease of stock by 50%, a reduction of storage and transport costs by up to 20%, as well as improvements in quality, in flexibility in quantity and productivity by more than 25 % were achieved, which equals a reduction in the total costs by about 8-12%.
Drawbacks of JIT
There are the following disadvantages of JIT:
- High supply chain risks. Due to the fact that JIT systems are focused on the reduction of inventory any fail from using JIT companies to adjust quickly to increased demand or suppliers’ distribution problems could lead to the stock outs and thus to the customer’s dissatisfaction.
- Little room for mistakes. Low level of inventory may hamper the possibility of reworking faulty products.
- Limitations of location choices. The external supplier is not free in his choice of location but is forced to settle down nearby his orderer to reduce the transport’s expense and the lead time, even though another location may be more suitable for competitive reasons.
- Negative effect on the environment. JIT procuration has negative effects on the environment as well as additional congestion is caused by frequent transports with little shipments.
These pitfalls make the importance of a precise planning and controlling of all JIT production processes obvious.
Applications of JIT
JIT success is different from industry to industry. Moreover some companies benefit more from JIT while others do not. For example, while there are semiconductor companies which successfully practice JIT, some of them don’t for the simple reason of high complexity of their operations for JIT implementation. On the other hand, that’s precisely the challenge of JIT-creation of a production set-up that is simple enough to allow JIT.
- ↑ http://www.toyota-global.com/company/vision_philosophy/toyota_production_system/just-in-time.html
- ↑ Operations Management, R. Dan Reid & Nada R. Sanders, 3rd Edition, Wiley 2007