Just in time - reduction in production time ,faster response to customer demand s and low
inventories.Reduce cost and save times on unnecessary actions or eliminate duplication of
Just-In-time manufacturing, or JIT, 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. 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.
The goal of JIT, therefore, is to minimize the presence of non-value-adding operations and
non-moving inventories in the production line. This will result in shorter throughput times,
better on-time delivery performance, higher equipment utilization, lesser space requirement,
lower dpm’s, lower costs, and greater profits.
JIT finds its origin in Japan, where it has been in practice since the early 1970’s. It was
developed and perfected by Taiichi Ohno of Toyota, who is now referred to as the father of
JIT. Taiichi Ohno developed this philosophy as a means of meeting customer demands with
minimum delays. Thus, in the olden days, JIT is used not to reduce manufacturing wastage,
but primarily to produce goods so that customer orders are met exactly when they need the
JIT is also known as lean production or stockless production, since the key behind a
successful implementation of JIT is the reduction of inventory levels at the various stations of
the production line to the absolute minimum. This necessitates 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
The JIT system consists of defining the production flow and setting up the production floor
such that the flow of materials as they get manufactured through the line is smooth and
unimpeded, thereby reducing material waiting time. This requires that the capacities of the
various work stations that the materials pass through are very evenly matched and balanced,
such that bottle necks in the production line are eliminated. This set-up ensures that the
materials will undergo manufacturing without queueing or stoppage.
Another important aspect of JIT is the use of a 'pull' system 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.
JIT is most applicable to operations or production flows that do not change, i.e., those that are
simply repeated over and over again. An example of this would be an automobile assembly
line, wherein every car undergoes the same production process as the one before it.
Pull system is better than push system in way that it doenst creat waste full inventories in
process thus reducing cost .