Just in time production (JIT): the other big pilar…

mayo 11, 2010

`Just-in-time’ is a management philosophy and not a technique.

It originally referred to the production of goods to meet customer demand exactly, in time, quality and quantity, whether the `customer’ is the final purchaser of the product or another process further along the production line.

It has now come to mean producing with minimum waste. “Waste” is taken in its most general sense and includes time and resources as well as materials. Elements of JIT include:

  • Continuous improvement.
    • 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 their own output.
    • Poka-yoke – `foolproof’ tools, methods, jigs etc. prevent mistakes
    • Preventative 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:
    • waste from overproduction.
    • waste of waiting time.
    • transportation waste.
    • processing waste.
    • inventory waste.
    • waste of motion.
    • waste from product defects.
  • Good housekeeping – workplace cleanliness and organisation.
  • 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.
  • Levelled / 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.

Background and history

JIT is a Japanese management philosophy which has been applied in practice since the early 1970s in many Japanese manufacturing organisations. It was first developed and perfected within the Toyota manufacturing plants by Taiichi Ohno as a means of meeting consumer demands with minimum delays . Taiichi Ohno is frequently referred to as the father of JIT.

Toyota was able to meet the increasing challenges for survival through an approach that focused on people, plants and systems. Toyota realised that JIT would only be successful if every individual within the organisation was involved and committed to it, if the plant and processes were arranged for maximum output and efficiency, and if quality and production programs were scheduled to meet demands exactly.

JIT manufacturing has the capacity, when properly adapted to the organisation, to strengthen the organisation’s competitiveness in the marketplace substantially by reducing wastes and improving product quality and efficiency of production.

There are strong cultural aspects associated with the emergence of JIT in Japan. The Japanese work ethic involves the following concepts.

  • Workers are highly motivated to seek constant improvement upon that which already exists. Although high standards are currently being met, there exist even higher standards to achieve.
  • Companies focus on group effort which involves the combining of talents and sharing knowledge, problem-solving skills, ideas and the achievement of a common goal.
  • Work itself takes precedence over leisure. It is not unusual for a Japanese employee to work 14-hour days.
  • Employees tend to remain with one company throughout the course of their career span. This allows the opportunity for them to hone their skills and abilities at a constant rate while offering numerous benefits to the company.

These benefits manifest themselves in employee loyalty, low turnover costs and fulfilment of company goals.

Supplies are delivered right to the production line only when they are needed. For example, a car manufacturing plant might receive exactly the right number and type of tyres for one day’s production, and the supplier would be expected to deliver them to the correct loading bay on the production line within a very narrow time slot.

Advantages of JIT

  • Lower stock holding means a reduction in storage space which saves rent and insurance costs
  • As stock is only obtained when it is needed, less working capital is tied up in stock
  • There is less likelihood of stock perishing, becoming obsolete or out of date
  • Avoids the build-up of unsold finished product that can occur with sudden changes in demand
  • Less time is spent on checking and re-working the product of others as the emphasis is on getting the work right first time

Disadvantages of JIT

  • There is little room for mistakes as minimal stock is kept for re-working faulty product
  • Production is very reliant on suppliers and if stock is not delivered on time, the whole production schedule can be delayed
  • There is no spare finished product available to meet unexpected orders, because all product is made to meet actual orders – however, JIT is a very responsive method of production.

” A company cannot decide to implement JIT; they must earn the right to use JIT by revising their quality procurement systems.”  – John Young, President of Hewlett-Packard.


1. Toyota the Developer of JIT System
Just-in-time manufacturing system has many advantages, but they are vulnerable to unexpected disruptions in supply. A production line can quickly come to a halt if essential parts are unavailable. Toyota, the developer of JIT, found this out the hard way. One Saturday, a fire at Aisin seiki Company’s plant in Aichi Prefecture stopped the delivery of all break parts to Toyota. By Tuesday, Toyota had to close down all of its Japanese assembly line. By the time the supply of break parts had been restored, Toyota had lost an estimated $15 billion in sales.

Source: “Toyota to Recalibrate ,'” International Herald Tribune, February 8, 1997.

2. PCs Just In Time Management
Del Computer Corporation has finally tuned its Just-in-Time system so that an order for a customized personal computer that comes in over the internet at 9 AM. can be on a delivery truck to the customer by 9 P.M. In addition, Dell’s low cost production system allows it to under price its rivals by 10% to 15%. This combination has made Dell the envy of the personal computer industry and has enabled the company to grow at five times the industry rate. How does the company’s just in time system deliver lower costs? “While machines from Compaq and IBM can languish on dealer shelves for two months Dell does not start ordering components and assembling computers until an order is booked. That may sound like no biggie, but the price of PC parts can fall rapidly in just a few months. By ordering right before assembly, Dell figures it s parts, on average, are 60 days newer than those in an IBM or Compaq machine sold at the same time. That can translate into a 6% profit advantage in components alone.”

Source: Gray McWilliams, “Whirlwind on the web, “Business Week, April 7, 1997.

3. Slashing Process Time
American Standards uses cell manufacturing to cut inventories and reduce manufacturing time. At its plant, England, it used to take as long as three weeks to manufacture a vacuum pump and another week to process the paper work for an order. Therefore customers had to place orders in advance. “Today Leeds has switched to manufacturing cells that do every thing from lathing to assembly in quick sequence. The result is a break through in speed. Manufacturing a pump now takes six minutes.”

Source: Shawn Tully, “Raiding a company’s Hidden Cash,” Fortune, August 22, 1994, PP 82-87.


MACDONALD’S JIT : http://www.youtube.com/watchv=QPaXpQqMKgg&feature=related

JIT: http://www.youtube.com/watch?v=phLNj_9leCo&feature=related

Companies Currently using JIT

  • Harley Davidson
  • Toyota Motor Company
  • General Motors
  • Ford Motor Company
  • Manufacturing Magic
  • Hawthorne Management Consulting
  • Strategy Manufacturing Inc.

Ten Arguments against the JIT Production Revolution

People naturally tend to harbor a mild affinity toward one another. Co-workers tend to harbor a very strong affinity with their system of “the way things are done,” which they have built together over the years. As far as they are concerned, no system could be better for them. They have no desire tochange it. After all, their routine is leveled and is very easy tolive with. Even in the finest-looking factories, life goes on inthe traditional, albeit obsolete, manner.

Improvement starts at the factory:

“Hey Joey, could you roll that set of machines over here?I want to link them up with this process.”

“Hey, no way. Why all the hassle?”

“Haven’t you heard? We’re dropping this lot production stuffand gearing up for one-piece flow.”

“Do you have any idea what kind of quality problems these changes are going to create?”

“Come on, move it. I want you to have this set-up for onepiece production before I come by again.”

“If you say so, but it won’t work.”

The three common excuses encountered at this point boil down to: “I don’t want to change things,” “It’s too much trouble,”and, “I’m afraid I’ll get laid off.”

Aside from these common excuses, I have been able to identify ten arguments against JIT that are often encountered on the path of JIT improvement.


Hence we can see that to have a Total JIT manufacturing system, a company-wide commitment, proper materials, quality, people and equipments must always be made available when needed. In addition; the policies and procedures developed for an internal JIT structure should also be extended into the company’s supplier and customer base to establish the identification of duplication of effort and performance feedback review to continuously reduced wastage and improve quality. By integrating the production process; the supplier, manufacturers and customers become an extension of the manufacturing production process instead of independently isolated processes where in fact in clear sense these three sets of manufacturing stages are inter-related and dependent on one another. Once functioning as individual stages and operating accordingly in isolated perspective; the suppliers, manufacturers and customers can no longer choose to operate in ignorance. The rules of productivity standards have changed to shape the economy and the markets today; every company must be receptive to changes and be dynamically responsive to demand. In general, it can be said that there is no such thing as a KEY in achieving a JIT success; only a LADDER; where a series of continuous steps of dedication in doing the job right every time is all it takes.



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