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Seminar On Just In Time Manufacturing ( JIT ) Full Report Download

Seminar On Just In Time Manufacturing ( JIT ) Full Report Download

ABSTRACT

JIT is a management philosophy that strives to eliminate sources of manufacturing waste by producing the right part in the right place at the right time. The Waste results from any activity that adds cost without adding value, such as moving and storing. The idea of producing the necessary units in the necessary quantities at the necessary time is described by the short term Just-in-time.
The implementation of this management philosophy in industries like the automobile industry can bring about a see saw change in both quality & quantity since in a JIT system, underutilized (excess) capacity is used instead of buffer inventories to hedge against problems that may arise. 
This seminar gives an over view of the JUST IN TIME technique by considering the TOYOTA PRODUCTION SYSTEM in detail.

INTRODUCTION

JUST IN TIME (JIT) is a management philosophy that strives to eliminate sources of manufacturing waste by producing the right part in the right place at the right time. Waste results from any activity, which adds cost without adding value, such as moving and storing. JIT (also known as stockless production) should improve profits and return on investment by reducing inventory levels (increasing the inventory turnover rate), improving product quality, reducing production and delivery lead times, and reducing other costs (such as those associated with machine setup and equipment breakdown). 

The idea of producing the necessary units in the necessary quantities at the necessary time is described by the short term Just-in-time. Just-in-time means, for example, that in the process of assembling the parts to build a car, the necessary kind of sub-assemblies of the preceding processes should arrive at the product line at the time needed in the necessary quantities. If Just-in-time is realized in the entire firm, then unnecessary inventories in the factory will be completely eliminated, making stores or warehouses unnecessary. The inventory carrying costs will be diminished, and the ratio of capital turnover will be increased.

ELEMENTS OF JIT
There are some very important elements in just in time manufacturing which makes it a successful philosophy. They are
·       Attacking fundamental problems - anything that does not add value to the product.
·       Devising systems to identify problems.
·       Striving for simplicity - simpler systems may be easier to understand, easier to manage and less likely to go wrong.
·       A product oriented layout - produces less time spent moving of materials and parts.
·    Quality control at source - each worker is responsible for the quality of his or her own output.
·      Poka-yoke - `foolproof' tools, methods, jigs etc. prevent mistakes
·  Preventive maintenance, Total productive maintenance - ensuring machinery and equipment functions perfectly when it is required, and continually improving it.
·    Eliminating waste.
There are seven types of waste:
1.     Waste from overproduction.
2.     Waste of waiting time.
3.     Transportation waste.
4.     Processing waste.
5.     Inventory waste.
6.     Unnecessary movement of people.
7.     Waste from product defects.
·    Good housekeeping - workplace cleanliness and organization.
·   Set-up time reduction - increases flexibility and allows smaller batches. Ideal batch size is 1item. Multi-process handling - a multi-skilled workforce has greater productivity, flexibility and job satisfaction.
·   Leveled / mixed production - to smooth the flow of products through the factory.
·   Kanbans - simple tools to `pull' products and components through the process.
· Jidoka (Autonomation) - providing machines with the autonomous capability to use judgement, so workers can do more useful things than standing watching them work.
·    Andon (trouble lights) - to signal problems to initiate corrective action. 

Just-in-time production 
The idea of producing the necessary units in the necessary quantities at the necessary time is described by the short term Just-in-time. Just-in-time means, for example, that in the process of assembling the parts to build a car, the necessary kind of sub-assemblies of the preceding processes should arrive at the product line at the time needed in the necessary quantities. If Just-in-time is realized in the entire firm, then unnecessary inventories in the factory will be completely eliminated, making stores or warehouses unnecessary. The inventory carrying costs will be diminished, and the ratio of capital turnover will be increased. 

However, to rely solely on the central planning approach which instructs the production schedules to all processes simultaneously, it is very difficult to realize Just-in-time in all the processes for a product like an automobile, which consists of thousands of parts. Therefore, in Toyota system, it is necessary to look at the production flow conversely; in other words, the people of a certain process go to the preceding process to withdraw the necessary units in the necessary quantities at the necessary time. Then what the preceding process has to do is produce only enough quantities of units to replace those that have been withdrawn. 

So Toyota’s slogan in manufacturing would be to produce in as small lots as possible with minimum cost as per market needs. If we look at parts that go into an assembly line in an automobile industry like Toyota we find that customization is maximum at the final stage. For e.g. Customer would chose color seats etc. this happens at the assembly. However at the aggregate stage a particular model would have a specific engine, transmission etc. many common parts go into different models. Finally the same steel and pig iron goes into different parts. Schematically it would as below. 

example of just in time production system

Planning system for materials can be based on the forecast where as planning system for final assembly must be based on accepted orders and there is a transition when one moves from raw material to finished product planning. 

References:
The Machine that changed the World - Womack, Jones and Roos 
Toyota Production System - Yasuhiro Monden
Study of Toyota production system– Shigeo Shingo

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