Just-In-time system of manufacturing, or JIT, is a management philosophy based on the concept of eliminating manufacturing wastes. The aim of JIT is to produce only the right amount and combination of parts at the right place at the right time. This 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.
Why should I be aware of this?
JIT involves lean production or stockless production, as reduction of inventory levels at the various stations of the production line to the absolute minimum is the key behind a successful implementation of JIT. This calls for good coordination between stations such that every station produces only the exact volume that the next station needs. On the other hand, a station pulls in only the exact volume that it needs from the preceding station.
By this process JIT minimizes the presence of non-value-adding operations and non-moving inventories in the production line, resulting in shorter throughput times, better on-time delivery performance, higher equipment utilization, lesser space requirement, lower costs, and greater profits.
How does this affect me?
Two mutually supporting components - people involvement and total quality control – are responsible for making the system one of continuous improvement. It calls for the active participation, involvement and cooperation of all its employees. The program requires teamwork, discipline, and supplier involvement.
Teamwork promotion is done through activities such as suggestion programs and quality circle programs. The former is conducted to encourage employees to give their ideas on how to improve a process. People working in similar types of operations meet at regular intervals in quality circles and discuss ways of improving the quality of their processes. Firms use the creativity of workers along with their teamwork and discipline to produce good quality products and services.
All about Just-in-time system
Just-in-time manufacturing process was first used by the Ford Motor Company and has been a part of the Japanese manufacturing industry for a very long time. Henry Ford's ideas and practices show many features seen in contemporary Japanese approaches. Ford, in the period from 1908 through the late 1920s, relied on a number of progressive and radical methods in manufacturing management; methods that were similar to the current Japanese methods. JIT is one of them.
JIT is a process where the suppliers, manufacturers as well as the customers are inter-related to each other for the successful competition of manufacturing. Planning the JIT is the most important process for setting up a JIT manufacturing system. The system calls for very clear objectives and it is also important to be equipped to integrate and optimize each and every step of the manufacturing system.
In the just-in-time system the capacities of the various work stations that the materials pass through are very evenly matched and balanced in order to eliminate bottle necks in the production line. Production flow is clearly defined and the production floor is set up in such a manner that the flow of materials through the line is smooth and unimpeded. This reduces material waiting time considerably.
Another important aspect is the 'pull' system used to move inventories through the production line. Under such a system, the requirements of the next station is what modulates the production of a particular station. It is, therefore, necessary under JIT to define a process by which the pulling of lots from one station to the next is facilitated.
No multiple suppliers
In the JIT process multiple suppliers are usually eliminated and quality assurance is higher. As all the parts used are of the same quality, the need for quality checks is almost eradicated, leading to higher productivity rates. The just-in-time manufacturing philosophy has been applied to many industries and businesses with very successful results.
However, the problem with just-in-time manufacturing is that the whole process lies in historical demand. It calls for correct assessment of materials and parts requirements. In the event of a rise or fall in demand for the product, it could have serious effects on the inventory process. Manufacturers have to make sure they have a sales forecast or reference in place to allow for these fluctuations in sales. If they do not have these figures, it could cause a serious problem for the just-in-time manufacturing process.
Toyota Motor Corp. and Honda Motor Co., Japan's two largest carmakers, may modify their so-called “just-in-time” manufacturing system to avoid possible supplier bankruptcies disrupting production.
The Japanese company may work with more parts makers and increase inventories to mitigate the effects of a collapse among its U.S. suppliers, at least half of whom also work for Detroit automakers.
Plunging demand in the U.S., the world's biggest auto market, contributed to Toyota on Dec. 22 forecasting its first operating loss since 1938. That was the same year the carmaker fully adopted the “just-in-time” model, according to its Web site. Under the system, companies avoid stocking inventories, preferring to take delivery of components as they are needed, to cut expenses. 
- Just-in-time manufacturing was first used by Henry Ford of the Ford Motor Company. He bought only the amount of material needed to fit into his plan of production. This gave him a rapid turnover and decreased the amount of money tied up in raw materials. 
- Ford's JIT process was adopted by many other car manufacturers. Toyota in Japan used the process with very satisfactory results; huge amounts of cash appeared as in-production inventory was built and then sold. 
- Just-In-Time (JIT) Manufacturing
- The Just-in-Time Manufacturing System
- JIT: New Concepts of Japanese Manufacturing