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.
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CONTENTS
CHAPTERS page
1. INTRODUCTION 1
2. JIT-BACKGROUND AND HISTORY 3
3. ELEMENTS OF JIT 5
4. CASE STUDY BY ZENTEC 8
5. THE TOYOTA PRODUCTION SYSTEM 11
6. TOYOTA’S JIT AND WESTERN PHILOSOPHY 23
7. KEYS TO SUCCESSFUL JIT IMPLEMENTATION 25
8. CONCLUSION 27
LIST OF FIGURES
Fig.4 (a) 9
Fig.4 (b) 9
Fig.5 (a) 20
Chapter 1
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.
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. JIT applies primarily to repetitive manufacturing processes in which the same products and components are produced over and over again. The general idea is to establish flow processes (even when the facility uses a jobbing or batch process layout) by linking work centers so that there is an even, balanced flow of materials throughout the entire production process, similar to that found in an assembly line. To accomplish this, an attempt is made to reach the goals of driving all queues toward zero and achieving the ideal lot size of one unit.
This new trend in engineering production, which originally refers to the production of goods to meet customer demand exactly, in time, quality and quantity, reduces wastage by nearly 55-75%. "Waste" in this context is taken in its most general sense and includes time and resources as well as goods. This concept can really change the phase of industrial production of goods like car & other important utilities.
Chapter 2
JIT – BACKGROUND AND HISTORY
JIT is a Japanese management philosophy, which has been applied in practice since the early 1980s in many Japanese manufacturing organizations. 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 market place 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 ethics 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 fulfillment of company goals.
Chapter 3
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.
The poka yoke system and Andon or visual control system is very significant, so are discussed in detail.
Poka yoke system:
Poka yoke or fool proofing is a method of 100% inspection. Poka yoke is preferred option to SQC. In SQC one has a sampling plan. If the sample is ok the lot is ok. However this does not mean that there are no defectives in the lot. When this lot goes to the market if a customer finds a defect then for him it is 100% defect. He is not concerned with batch or sample. Therefore SQC is “rationalization of method of inspection”. It does not ensure defects are not produced at all. Poka yoke does this. When a washing machine is packed an instruction manual is placed in the carton. Packing takes place on a conveyer out of one million cartons packed per month 7-8 customers complain that instruction booklets were not received. When a complaint is received the packer was asked to be more cautious. For a few days there were no complaints and then once again it would occur. Fool proofing was carried out by providing an electric switch on the box from which the instruction booklet was withdrawn. Now every time an instruction booklet was with drawn the electric switch activated. This allowed the carton to move to the next stage of the conveyer using an interlock no more customer complaints for missed instruction manuals. This is a classical example of poka yoke in action.
Andon system:
JIT system puts emphasis on prevention of recurrence of a problem. Using andon board a supervisor immediately comes to know where a problem occurs. All employees are allowed to stop production when a problem occurs. Stopping of machines or production lines with a view to permanently eliminate the problem. One must not relieve pain by using pain killers, one must go to the root of the problem and once and fro all eliminate it. By stopping machines or production lines everyone’s energy is focused in finding a permanent solution. This in a way defines management philosophy which does not look for short term gains but for long term results. Very often when a problem occurs emergency measures are taken parts are reworked or salvaged which then becomes a standard practice. This causes waste. If a company management accepts this philosophy then it is advisable that it does not attempt a JIT production system.
Chapter 4
CASE STUDY BY ZENTEC
Any production system must aim to produce at minimum cost. Cost reduction in a normal production system is achieved through mass production on highly productive machines with high capacity utilization. Components are produced using tooling whose change over is time consuming, there fore common sense called for large batches over which set up change time could be distributed . Large batches of parts meant that all of them are not used at the same time .this resulted in large ware houses. It also resulted in planning production, based on market fore cast.
Zentec process consulting and management made a case study, before & after the implementation of the JIT philosophy on the change of Process Improvement through Offsite Warehouse Removal
Fig.4 (a)
Fig.4 (b)
If the market is a large and a growing one and forecasts are correct, then this would not be a problem. The American market was just that. So it is safe to state that the American production system resulted from the characteristics of its market. For example, a refrigeration company, making two sizes of refrigerators, one small and one large would set up separate lines or plants, because the market justified it.
On the other hand the Japanese market is much smaller and fragmented. Variety is large and volumes are low. Space is also a limitation. It was there fore a fit situation for the evolution of a production system to cater to this kind of market. So the philosophy of just in time evolved.
No study of JIT philosophy is complete without considering The Toyota production system, a Case Study of Creativity and Innovation in Automotive Engineering.
Chapter 5
THE TOYOTA PRODUCTION SYSTEM
Automobile Manufacturing
Today, automobile manufacturing is the world's largest manufacturing activity. After First World War, Henry Ford and General Motors' Alfred Sloan moved world manufacture from centuries of craft production led by European firms into the age of mass production. Largely as a result, the United States soon dominated the world economy.
Toyota Production System
After Second World War, Eiji Toyoda and Taiichi Ohno at the Toyota motor company in Japan pioneered the concept of Toyota Production System. The rise of Japan to its current economic pre-eminence quickly followed, as other companies and industries copied this remarkable system. Manufacturers around the world are now trying to embrace this innovative system, but they are finding the going rough. The companies that first mastered this system were all head-quartered in one country-Japan. However, many Western companies now understand Toyota Production System, and at least one is well along the path of introducing it. Superimposing this method on the existing mass-production systems causes great pain and dislocation.
Perhaps the best way to describe the Toyota production system is to contrast it with craft production and mass production, the two other methods humans have devised to make things.
Craft Production methods
The craft producer uses highly skilled workers and simple but flexible tools to make exactly what the customer ask for—one item at a time. Few exotic sports cars provide current day examples. The idea of craft production is good, but the problem with it is obvious: Goods produced by the craft method—as automobiles once were exclusively—cost too much for most of us to afford. So mass production was developed at the beginning of the twentieth century as an alternative.
Mass production methods
The mass-producer uses narrowly skilled professionals to design products made by unskilled or semiskilled workers tending expensive, single-purpose machines. These churn out standardized products in very high volume. Because the machinery costs so much and is so intolerant of disruption, the mass-producer keeps standard designs in production for as long as possible. The result: The customer gets lower costs but at the expense of variety and by means of work methods that most employees find boring and dispiriting.
The Toyota motor corporation, by contrast, combines the advantages of craft and mass production, while avoiding the high cost of the former and the rigidity of the latter. Toward this end, they employ teams of multi-skilled workers at all levels of the organization and use highly flexible and increasingly automated machines to produce volumes of products in enormous variety. .
Perhaps the most striking difference between mass and Toyota production system lies in their ultimate objectives. Mass-producers set a limited goal for themselves— "good enough," which translates into an acceptable number of defects, a maximum acceptable level of inventories, a narrow range of standardized products. Lean producers on the other hand, set their sights explicitly on perfection.
Basic idea and Framework
The Toyota production system is a technology of comprehensive production management the Japanese invented a hundred years after opening up to the modern world. The basic idea of this system is to maintain a continuous flow of products in factories in order to flexibly adapt to demand changes. The realization of such production flow is called Just-in-time production, which means producing only necessary units in a necessary quantity at a necessary time. As a result, the excess inventories and the excess work-force will be naturally diminished, thereby achieving the purposes of increased productivity and cost reduction.
The basic principle of Just-in-time production is rational; that is, the Toyota production system has been developed by steadily pursuing the orthodox way of production management. With the realization of this concept, unnecessary intermediate and finished product inventories would be eliminated. However, although cost reduction is the system's most important goal, it must achieve three other sub-goals in order to achieve its primary objective. They include:
1. Quantity control, which enables the system to adapt to daily and monthly fluctuations in demand in terms of quantities and variety;
2. Quality assurance, which assures that each process will supply only good units to the subsequent processes;
3. Respect-for-humanity, which must be cultivated while the system utilises the human resource to attain its cost objectives.
It should be emphasized here that these three goals cannot exist independently or be achieved independently without influencing each other or the primary goal of cost reduction. All goals are output of the same system; with productivity as the ultimate purpose and guiding concept, the Toyota production system strives to realize each of the goals for which it has been designed. Before discussing the contents of the Toyota production system in detail, an overview of this system is in order. The outputs or result side as well as the inputs or constituent side of the production system are depicted.
A continuous flow of production, or adapting to demand changes in quantities and variety, is created by achieving two key concepts: Just-in-time and Autonomation. These two concepts are the pillars of the Toyota production system.
Just-in-time basically means to produce the necessary units in the necessary quantities at the necessary time. Autonomation ("Jidoka" in Japanese) may be loosely interpreted as autonomous defects control. It supports Just-in-time by never allowing defective units from the preceding process to flow into and disrupt a subsequent process. Two concepts also key to the Toyota production system include Flexible work force ("Shojinka" in Japanese) which means varying the number of workers to demand changes, and Creative thinking or inventive ideas ("soikufu"), or capitalizing on workers suggestions.
To realize these four concepts, Toyota has established the following systems and methods:
1. Kanban system to maintain Just-in-time production
2. Production smoothing method to adapt to demand changes
3. Shortening of set-up time for reducing the production lead time
4. Standardization of operations to attain line balancing
5. Machine layout and the multi-function worker for flexible work force
6. Improvement activities by small groups and the suggestion system to reduce the work force and increase the worker's morale.
7. Visual control system to achieve the Autonomation concept
8. Functional Management system to promote company-wide quality control.
Kanban system
A kanban is a card that is attached to a storage and transport container. It identifies the part number and container capacity, along with other information. There are two main types of kanban (some other variations are also used):
1. Production Kanban (P-kanban): signals the need to produce more parts
2. Conveyance Kanban (C-kanban): signals the need to deliver more parts to the next work center (also called a "move kanban" or a "withdrawal kanban")
A Kanban system is a pull-system, in which the kanban is used to pull parts to the next production stage when they are needed; a MRP system (or any schedule-based system) is a push system, in which a detailed production schedule for each part is used to push parts to the next production stage when scheduled. The weakness of a push system (MRP) is that customer demand must be forecast and production lead times must be estimated. Bad guesses (forecasts or estimates) result in excess inventory and the longer the lead-time, the more room for error. The weakness of a pull system (kanban) is that following the JIT production philosophy is essential, especially concerning the elements of short setup times and small lot sizes.
A Withdrawal Kanban details the kind and quantity of product which the subsequent process should withdraw from the preceding process, while a Production Kanban specifies the kind and quantity of the product which the preceding process must produce.
Concept of kanban is explained as a device which prevents over production. For example on a single track line in the railways a key is given to the train driver as he leaves the railway station. When he reaches the next station he gives this key to the station master. The key now unlocks the signal allowing the train to move forward. Another key is now given which the train driver hands over to the next station. The key in this example is the kanban and the train is the quantity of material which passes from one process to the next. The train in the opposite direction returns the key or kanban. Please note it is only one train and therefore quantity is controlled
In case of factories a kanban is a document which controls the quantity to be produced and in what time. Final assembly personnel are given the customer’s order. As they draw the material they hand over a kanban to the proceeding process to replace the material drawn. The proceeding process manufactures the product in the quantity and time as per the kanban and delivers it to the succeeding process. In turn it consumes the material while processing and releases a kanban to its proceeding process. In this manner the chain continues throughout the factory to the stage of raw material.
Kanban, which is a document, carries three types of information.
It identifies the product or material.
It indicates the stage of processing to be carried out, till when it is to be carried out and in what amounts it is to be carried out.
It indicates from where to where the material or products to be transported.
Since production is repetitive in an automobile industry, kanban can be re used. By limiting the number of kanbans in circulation one can eliminate the waste of over production and minimize stocks. A kanban indicates total time of delivery. This means from the time kanban is released to the parts being physically available at the required point. Say in an assembly 5 piece are consumed in an hour. Kanban time is two hours. Then there may be two kanban of 5 pieces each in circulation. Continuous improvement would be carried out to reduce the delivery time to one hour and eliminate one kanban. Further improvements may reduce the quantity of the kanban
Dual-card Kanban Rules
1. no parts made unless P-kanban authorizes production
2. exactly one P-kanban and one C-kanban for each container (the number of containers per part number is a management decision)
3. only standard containers are used, and they are always filled with the prescribed (small) quantity
Productivity Improvement with Kanban
1. deliberately remove buffer inventory (and/or workers) by removing kanban from the system
2. observe and record problems (accidents, machine breakdowns, defective products or materials, production process out of control)
3. take corrective action to eliminate the cause of the problems
Many people think the Toyota production system a Kanban system: this is incorrect. The Toyota production system is a way to make products, whereas the Kanban system is the way to manage the Just-in-time production method.
In short, the kanban system is an information system to harmoniously control the production quantities in every process. It is a tool to achieve just-in-time production. In this system what kind of units and how many units needed are written on a tag-like card called Kanban. The Kanban is sent to the people of the preceding process from the subsequent process. As a result, many processes in a plant are connected with each other. This connecting of processes in a factory allows for better control of necessary quantities for various products.
The Kanban system is supported by the following:
• Smoothing of production
• Reduction of set-up time design of machine layout
• Standardization of jobs
• Improvement activities
• Autonomation
Autonomation
In order to realize Just-in-time perfectly, 100 per cent good units must flow to the prior process, and this flow must be rhythmic without interruption. Therefore, quality control is so important that it must coexist with the Just-in-time operation throughout the Kanban system. Autonamation means to build in a mechanism a means to prevent mass-production of defective work in machines or product lines. Autonamation is not automation, but the autonomous check of abnormality in the process. The autonomous machine is a machine to which an automatic stopping device is attached. In Toyota factories, almost all the machines are autonomous, so that mass-production of defects can be prevented and machine breakdowns are automatically checked. The idea of Autonomation is also expanded to the product lines of manual work. If something abnormal happens in a product line, the worker pushes stop button, thereby stopping his whole line. For the purpose of detecting troubles in each process, an electric light board, called Andon, indicating a line stop, is hung so high in a factory that it can easily be seen by everyone. The Andon in the Toyota system has an important role in helping this autonomous check, and is a typical example of Toyota's "Visual Control System."
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 realised 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 realise 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 customisation is maximum at the final stage. For e.g. Customer would chose colour 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.
Fig 5. (a)
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.
The result of Toyota’s planning process is as follows; if a special car is ordered in Japan at Toyota dealer, it is immediately transferred to head office and onwards to Toyota motors .through computers this information is sent to the assembly plant. With in two days the required car is manufactured. It takes maximum six days to transport it and another two days are kept as allowance. Thus a customer’s special car can be delivered in ten days. In contrast if one wishes to purchase a specific colour car in India the dealer does not have in stock or it can be delivered when the company takes up a batch of that particular colour. In case the colour is not a standard one, one may never get it at all. We have come some way from Henry Fords “we can deliver all colours as long as they are black”.
How does Toyota assemble a special car in two days? Does it mean that manufacture of car really take place in just two days? The answer to these questions can be obtained by observing the planning and execution system in a little detail.
Planning
Using strong marketing system an yearly plan is prepared. This consists of assessment of market size and share of Toyota. Rough indication of models and quantities.
A tentative monthly production plan is prepared two months in advance. This includes information on types of models and number of sets.
On the fifteenth day of previous month, manufacturing models, types and other details are firmed up. At this stage leveling of production is carried out and quantity of production per day model wise is decided and informed to the production lines. This is again informed to venders.
On twenty fifth day of previous confirmed plan of first ten days is released. On fifth day of the month confirmed plan for next ten days and on fifteenth day of the month final ten days plan is released. This is what is called the T plan or ten day plan.
Global adaptation
Since Toyota production system has been created from actual practices in the factories of Toyota, it has a strong feature of emphasizing practical effects, and actual practice and implication over theoretical analysis. This system can play a great role in the task of improving the constitutions of the companies, world-wide (especially those of the automobile industry).
Chapter 6
TOYOTA’S JIT AND WESTERN PHILOSOPHY
There are striking differences between the Toyota’s just in time manufacturing philosophy and the western philosophy. The major differences can be tabulated as below.
Factors
Toyota's JIT
Western Philosophy
1. Inventory A liability. Every effort must be extended to do away with it. An asset. It protects against forecast errors, machine problems, and late vendor deliveries.
More inventories are “safer".
2. Lot sizes Immediate needs only. A minimum replenishment is desired for both manufactured and purchased
parts.
Formulas. They’re always revising quantity the optimum lot size with some formula based on the trade-off between the cost of inventories and the cost of set up.
3. Set ups Make them insignificant.
This requires either extremely rapid changeover to minimize the impact on production, or the availability of extra machines already set up. Fast changeover permits
small lot sizes to be practical, and allows a wide variety of parts to be made frequently.
Low priority. Maximum output is the usual goal. Rarely does similar thought and effort go similar thought and effort go
into achieving quick changeover
4. Queues Eliminate them. When problems occur, identify the causes and correct them. The correction process is aided when queues are small. If the queues are small, it surfaces the need to identify and fix the cause. Necessary investment. Queues permit succeeding operations to continue in the event of a problem with the feeding operation. Also, by providing a selection of jobs, the factory management has greater opportunity to match up varying operator skills and machine capabilities, combine set ups
and thus contribute to the
efficiency of the operation
5. Vendors Co-workers. They're part of the team. Multiple deliveries for all active items are expected daily. The vendor takes care of the needs of the customer, and the customer
treats the vendor as an
extension of his factory.
Adversaries. Multiple sources are the rule, and it's typical to play them off against each other.
6. Quality Zero defects. If quality is 100%, production is in jeopardy. Tolerate some scrap. They usually track what the actual scrap has been and develop formulae for predicting it.
7. Equipment maintenance Constant and effective. Machine break downs must be minimal. As required. But not critical because we have queues available.
8. Lead times Keep them short. This simplifies the job of marketing, purchasing, and manufacturing as it reduces
the need for expediting The longer the better. Most foremen and purchasing agents want more lead time, not less
9. Workers Management by consensus Changes are not made until consensus is reached, whether or not a bit of arm twisting is involved. The vital ingredient of "ownership" is achieved. Management by edict. New systems are installed in spite of the workers, not thanks to the workers. Then they concentrate on measurements to determine whether or not they're doing it.
Chapter 7
KEYS TO SUCCESSFUL JIT IMPLEMENTATION
The following are some of the keys for successful JIT implementation
1. Stabilize and level the master production schedule (MPS) with uniform plant loading: create a uniform load on all work centers through constant daily production (establish freeze windows to prevent changes in the production plan for some period of time) and mixed model assembly (produce roughly the same mix of products each day, using a repeating sequence if several products are produced on the same line). Meet demand fluctuations through end-item inventory rather than through fluctuations in production level.
2. Reduce or eliminate setup times: aim for single digit setup times (less than 10 minutes) or "one-touch" setup -- this can be done through better planning, process redesign, and product redesign.
3. Reduce lot sizes (manufacturing and purchase): reducing setup times allows economical production of smaller lots; close cooperation with suppliers is necessary to achieve reductions in order lot sizes for purchased items, since this will require more frequent deliveries.
4. Reduce lead times (production and delivery): production lead times can be reduced by moving work stations closer together, applying group technology and cellular manufacturing concepts, reducing queue length (reducing the number of jobs waiting to be processed at a given machine), and improving the coordination and cooperation between successive processes; delivery lead times can be reduced through close cooperation with suppliers, possibly by inducing suppliers to locate closer to the factory
5. Preventive maintenance: use machine and worker idle time to maintain equipment and prevent breakdowns
6. Flexible work force: workers should be trained to operate several machines, to perform maintenance tasks, and to perform quality inspections. In general, the attitude of respect for people leads to giving workers more responsibility for their own work.
7. Require supplier quality assurance and implement a zero defects quality program: errors leading to defective items must be eliminated, since there are no buffers of excess parts. A quality at the source (jidoka) program must be implemented to give workers the personal responsibility for the quality of the work they do, and the authority to stop production when something goes wrong. Techniques such as "JIT lights" (to indicate line slowdowns or stoppages) and "tally boards" (to record and analyze causes of production stoppages and slowdowns to facilitate correcting them later) may be used.
8. Small-lot (single unit) conveyance: use a control system such as a kanban (card) system to convey parts between workstations in small quantities (ideally, one unit at a time). In its largest sense, JIT is not the same thing as a kanban system, and a kanban system is not required to implement JIT (some companies have instituted a JIT program along with a MRP system), although JIT is required to implement a kanban system and the two concepts are frequently equated with one another.
Chapter 8
CONCLUSION
From this study, it is understood that, in this modern competitive world, where only those industries, which provide maximum customer satisfaction at attracting prices can succeed, the JIT system plays an important role, as it reduces the manufacturing time & wastage, during production. Thus it increases the amount of goods produced and decreases the cost of production of these goods.
This seminar stresses the need to implement JIT technique in Automobile industries &other modern industries where large-scale production takes place.
References:
The Machine that changed the World - Womack, Jones and Roos
Toyota Production System - Yasuhiro Monden
Study of Toyota production system– Shigeo Shingo
