PRINCIPLES OF JIT- JUST IN TIME

1. SUJEET S.TAMBE
PRINCIPLES OF JIT
Just in Time (JIT) pioneered by Toyotain the 1950s and adopted
successfully all over the world entails eliminating waste and improving product
quality to maximize returns on investment. The basic JIT principles are to make
only what is needed, when needed, and in the amount needed.
 JIT Elimination of Waste
The core principle objective of Just in TIme (JIT) is to improve process
efficiency by eliminating waste. Toyota's Fujio Cho defines waste as "anything
other than the minimum amount of equipment, materials, parts, and workers,
which are absolutely essential to production" .
The seven common types of waste identified by JIT include:
1. processing waste
2. waste due to idling time of machinery
3. waste due to productdefects
4. waste of motion or faulty working techniques
5. waste related to transportation
6. waste from overproduction
7. inventory waste
JIT elimination of waste deploys tools such as total quality management,
continuous quality improvement, focused factory, reducing setup times, flexible

2. SUJEET S.TAMBE
resources, group technology layout, and pull production system to eliminate
waste.
 Quality at the Source (Jidoka)
Jidoka or ensuring quality at the sourceranks amongst the major JIT
principles. This principle entails identification and correction of problems at the
manufacturing stage itself, as soonas it occurs.
JIT provides for jidoka through automation that caters to the automatic
working of the assembly line and complete shut down upon detection of error.
The productionline resumes only after rectification of the error.
Jidoka makes inspection and quality control a part of the production process
rather than a separate activity, and places the responsibility for quality on
everyone in the company rather than the quality team alone.
 Simplification
The third of the major JIT principles is simplification or using minimum
resources to attain process efficiency. The JIT principle holds that excess of any
kind masks problems such as low quality raw materials, unreliable vendors,
defects in machinery, and the like. Removing the excess makes problems
apparent.
JIT systems strive to attain zero work in process inventory buffers and zero
ending finished goods inventory to ensure smooth process flow, elimination of
storage space, and costsavings. JIT promotes a demand driven “pull” system

3. SUJEET S.TAMBE
where the process starts when the customer places an order that triggers the
production, which in turn triggers a call for resources. Each stage in the
production process manufactures only what is required for the next stage.
“Kanbans” or instructions, usually by cards, provide each worker with specific
instructions on what to do and what to use.
 Cellular Manufacturing System
Group technology or Cellular manufacturing is another major JIT principle.
The Cellular manufacturing system advocates that segmented and product
focused manufacturing is much simpler than a linear process oriented
manufacturing.
JIT institutes strategic capacity management techniques such as multiple
small machines instead of a large bulky machine that requires constant
production for profitability and others towards this end.
 RespectforPeople
Among the major JIT principles is respect for people at all levels, be it
employees, customers, suppliers or management. Success ofJIT depends on
identification of what the customer needs and fulfilling the request in the best
possible manner.
Success ofJIT depends on
1. clear and effective communication among all the stakeholders

4. SUJEET S.TAMBE
2. employees empowered to make decisions and cross-trained to
handle many machinery to ensure smoothflow of the product
3. suppliers understanding and fulfilling demand for specific
components at the right time
The management that respects people and works towards such people
related critical success factors succeeds in reaping the benefits of JIT.