history of lean manufacturing.ppt

8/10/2019 History of Lean Manufacturing.ppt

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Toyota Production System (Just In Time System)

Started after the World War II in Japan for theToyota Autmobile System

Constraints Toyota had encountered:

They could not compete with the giants like Ford in

the foreign market and so they depended upon thesmall local markets.

They had to bring down the raw materials fromoutside

They had to produce in small batches

They havent had much capital to work with


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Taiichi Ohno with right hand Dr. ShigeoShingotook the challenge and for the next

three decades (after WWII), he built the JITSystem.


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Although, JIT concept was mastered inJapan, and the roots of this concept goes

into the 16thcentury.

Eli Whitneys concept of Interchangeable

Parts said to be the very initial beginningof this concept.


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But first or at least famous implementation

of something similar to JIT happened acentury later in manufacturing of FordModel T (in 1910) automobile design.

Manufacturing was based on line assembly. Every part moved without interruptions to

the next value adding point.

Parts are manufactured and assembled in acontinuous flow. (PUSH SYSTEM)


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Although Henry Ford may not haveunderstood the basics behind his system,

but it saved lots of money and made himthe richest man at that time.

Despite his success in the initial years,

Fords system had it drawbacks due to thepush strategy implemented in Fordssystem.


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Fords System drawbacks (push system):

They relied on keeping machine busy without

thinking about the final outcome;They had huge stocks in the form of finished

goods and in the form of Work In Progress

(WIP). This led to the inflexibility of thesystem.

Wasted money unnoticed;

Poor handling of human resources, which ledto have a less motivated set of people in theorganization.


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But in Japan:

They studied the system very well and saw

the problems that Ford system had. But itscore concept was still obeyed. This is thecontinuous flow value of system. Anything

distracting it, is treated as a waste(muda). Ohno and Shingo understood the

drawbacks in the push system and

understood the role played by theinventory.


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Ohno and Shingo understanding led to PullSytem rather than the Push System, where

the parts are produced only when they arepulled by the process before that.

This is similar to the concepts in the

supermarkets, wherein, shelves are onlyrefilled with new ones once they are emptied(which means people are buying the product).


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PULL SYSTEM:

Pull means that no one upstream shouldproduce a good or service until the customerdownstream asks for it.

Start with the real customer demand and workbackwards through all the steps required to

deliver the desired product to the customer. Replenishment is based on actual consumption

and not on anticipated future needs.


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Lean system developed in Toyota from1949 to 1975 virtually unnoticed by others

even within Japan. In oil crisis in 1973 where Japan economy

suffered and most industries had losses,

Toyota had overcame these problems andstood out from the rest. And this was theeye opener for other Japanese firms to

implement the same system.


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This (lean) system got popular in the westernworld with the book The Machine That Change

the World written by James Womack in 1990. This book was aimed to give the history of the

automobile with the plant details of some ofthese manufacturers.

He gave the name Lean Manufacturing to thissystem.

This was the eye opener for the western world.

Thereafter, the concepts were practiced all overthe world.


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history of lean manufacturing.ppt

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