Toyota Production System
The Toyota Production System (TPS, Japaneseトヨタ 生産 方式, Toyota Seisan hōshiki ) is a concept in order to avoid any kind of waste that has evolved over time at the company Toyota and which is constantly evolving. ' Founder ' is Sakichi Toyoda, who invented the automatic stopping loom in 1902, thus laying the basis for the Jidoka principle. His son, Kiichiro Toyoda in 1937 became the first chairman of Toyota Motor Corporation and developed the " just-in -time" thoughts. Reasons for the emergence of the TPS were, firstly, the shortage of raw materials in Japan and on the other hand, the isolation policy of the U.S. towards Japan, who wanted to prevent in the automotive industry, among others, the Japanese competition. Even after the end of the Second World War, Japan did not receive economic aid from the United States, and so the Japanese companies had to start with their own ( modest ) resources and means with the automobile production. As the resources were scarce, you had to deal very economical with the existing, avoid waste and try to organizational means to improve the processes and procedures to improve quality.
After the Second World War, the TPS was systematically developed by the engineer and production manager Taiichi Ohno and supplemented by many elements and methods. His ideas and principles he wrote down in a book published in Japan in 1978 and was published ten years later in English. In the preface to the English edition T. Ohno writes: "The starting concept of the Toyota production system which, as I have emphasized several times, a thorough elemination of waste ". Starting point of the concept is followed by the removal of any waste, be it in the production process or in the indirect area, ie in the range of service and the administration.
The Toyota Motor Corporation itself has their production system officially " booklet " for the first time in 1992 in a published. This has been extensively revised and published again in 1998. In the preface states: "The TPS is a framework for conserving resources by Eliminating waste. People who participate participation in the system learn to identify expenditures of material, effort and time did do not generate value for customers " and more " we have avoid a ' how-to ' approach. The booklet is not a manual. Rather it is an overview of the concepts, did underlie our production System. It is a reminder did Lasting clan gains in productivity and quality are possible Whenever and wherever Management and Employees are united in a commitment to positive change ". The TPS is therefore not a recipe book that you simply must only apply, how something is done and you are successful. Rather, it provides a framework to avoid waste, it is a concept, a way of thinking and behavior that must be lived and constantly evolving.
The goal of TPS is the highest possible productivity coupled with high product quality and on-time delivery to the customer. The TPS consists of two columns.
The information, which is to be produced and in what quantities will be reported according to the pull system to the upstream. This is only the ( post- ) produce, which is then also consumed. For the concrete material flow control, different methods can be used such as Kanban, the two-tank principle or the principle cart. The results include minimal material resources in the process. Such a process can only work reliably if the qualifications of the staff, the availability of the machines and the intermediates generated in the process to meet very high standards. Very early Toyota has implemented the quality strategies by the American William Edwards Deming, whose ideas are encountered in his home country on deaf ears with great success.
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The elements of the Toyota Production System
- Objective: Production in the customer cycle
- Elimination of waste in the production process
- Synchronization of processes
- Standardization of processes
- Avoid errors
- Improvement of the production
- Qualification and Training of employees
- Continuous improvement of processes
Production in the customer cycle
Done the final assembly of the suppliers more products than the customer decreases at the same time, then build with the distributor inventories of finished parts. Produces the final assembly of the supplier, the customer uses less than in the period, its finished goods warehouse is eventually empty, and he is no longer able to deliver.
Only when the final assembly of the supplier produces the same beat as the customer will order the products, a construction of finished parts inventory, or delivery demolition is unavoidable. What is true for the synchronization of the suppliers with the external customers, also applies to the synchronization of internal customers and internal suppliers.
If the final assembly in the same clock produced as the external customer and, starting from the final assembly, all upstream areas only nachproduzieren what has just been consumed, it is called a towing system ( engl. pull system ) that produces synchronous to the customer cycle, so just-in- time (JIT ) or just in sequence (JIS).
While customer orders often vary widely, it is easiest for the production, from the same part to produce the same amount every day. This conflict is trying to solve with a smoothing: It is not necessary to adjust production to the daily orders. It is quite sufficient if one long drives a constant production program, for example one week. You put once fixed a week, which quantities are to be manufactured in the following week of each part per day. This weekly program leveled the order fluctuations of the customer and provides a smooth and continuous production during the week.
Elimination of waste
Work is composed of value added and waste. Processing time on the machine are value added. Waiting of the operator to the end of the machining operation or transporting parts are waste.
In most factories, there are still high material stocks, during and after the manufacturing process. This allows you to compensate for missing parts on the supply side, machine failures or poor manufacturing quality, without this having an impact on the end user. It is even so intended, because it is assumed that there is a problem. This state is not perceived as a waste, because it is the norm in most factories.
So one has to avoid the problems that are to be compensated by wasting. This implies in particular that the material stocks in the manufacturing process can be drastically reduced - which, however, has controlled to take place because of all the problems occurring then a solution must be found to prevent the loss of production.
Aim is to replace waste through value creation. In the Toyota Production System, a distinction seven types of waste. The waste is referred to in Japanese as Muda. One way to make waste visible, are the so-called Andon Andon boards or signals. The procedure for the detection and elimination of waste is referred to in the literature as Muda elimination. The TPS distinguishes the following seven types of waste:
The inventor of the Toyota Production System, Taiichi Ohno was limited to seven types of waste which by Liker, Keyte and Locher to an eighth type, the underestimation or non-use of the skills of employees, have been added. Also, the failure to prevent risks, machine failures due to lack of maintenance ( lack or loss of Total Productive Maintenance), lack of information (especially in ERPs ) and product designs which can not meet customers' needs are considered types of waste.
Synchronization of processes
In the conventional production system determines a central planning and control system based on set-up time optimal lot sizes for independently operating production areas, which are organized according to the workshop principle. In this case, each region pushes its parts in a buffer for the subsequent process ( sliding end system ). In processing times of less than an hour, the production cycle time is often several weeks.
The Toyota production system only produced what has just been consumed. With fast tool changes the production of small batches is economical. The throughput time ( lead time ) is almost identical to the pure processing time (cycle time). The material is constantly in flux. The cycle time is reduced compared to the shifting system by over 90%. This is achieved mainly by switching from the production lot sizes in the workshop principle to the one-off production in the flow principle ( One-Piece -Flow).
The information, which is in what quantity to produce is passed from downstream by means of a so-called kanban to the upstream region ( Pulling System / pull principle). Thus, the PPS system loses its central control function. It has only documentation function for parts or customer master data. The control function is performed by kanban cards that carry the control data locally.
The material in the process can be gradually reduced by up to 90 percent. In parallel, the problems encountered, which now come to light solved.
Standardization of processes
In a well-organized factory is clearly defined what material and in what quantity on which area is and how and with what worked at various jobs. These rules are documented and only a suggestion for improvement leads to a change in the rules of the game. Only the one who knows where he stands, can determine whether he is improving.
Standards must be visible visualized in the factory for everyone. The publication of standards, however, is only useful if you can see at a glance whether they are adhered to. Both the employee as well as the responsible managers must be able to recognize immediately whether the process standards are being met or not. Toyota herein uses the principle of visualization. Standard deviations have to stand right in the eye. For example, storage places for maintenance tool are marked with the outline. If the tool is not in place, is due to the outline immediately clear which tool should be here.
To ensure ongoing compliance with standards, they must be audited. Management at all hierarchical levels took part in the audit. For this, a detailed audit plan to create, from which it is clear who when which performs audit. The auditing process is not perceived by employees as a control, since they define their default worksheets even the standard values , which is why the interest of the management in compliance with the standards process is rather perceived as positive. Toyota builds on standards, but which must be constantly improved by the employee ( kaizen ). This makes it possible Toyota to offer a variety to monotonous, standardized processes.
Avoid errors
With minimal material stocks in the process, it is essential that only good parts are passed on to the downstream area. This assumes that the product quality is constantly monitored not only by the audit. To this end, all employees are properly trained to production and logistics and more aware of this problem. The way to do this is known as Total Quality Management ( TQM).
Every employee can make mistakes. The more points it must examine, the greater the likelihood that he sees something. Therefore, the number of its test points must be reduced to a minimum, which is not a contradiction to the previous section.
Automatic testing ( Jidoka ), the self-control of the machine is achieved by simple sensors or guides, but the tools above may not be an additional risk of litigation. Thus, the machine is able to detect whether the tolerances are maintained itself. This is not the case, it will stop automatically. In Japan they are called methods Poka Yoke, which means that they would " avoid unintentional errors ". Recognizes an employee an error that is not quickly remedied, he pulls the Andon cord to stop the production line.
Improvement of the production
The production employees are trained maintenance and can technically correct faults, to a certain degree even. Only if they do not succeed in the repair within a defined period, the central maintenance team in action (autonomous maintenance) occurs. The goal is to find if a fault occurs, the actual cause of this and then sustainably eliminate. This process starts after the so-called " 5 -W - method " in front, where you can also find the actual cause of the fault with the " five-time questions about the why ," in almost all cases. The will to sustainably solve problems or disorders, ie so that they never occur more is especially emphasized by the possibility that the workers stop the assembly line via a ripcord and thus can stop the production.
The decentralization of the maintenance workers are involved in the responsibility for the functioning of their machines. Since they do not automatically have break at machine faults, their motivation to avoid such situations, very high. Concretely, this means that checkpoints that are accessible without disassembly of machine parts and were often irregularly or not checked by the central maintenance, will now be checked daily (preventive maintenance). This method is referred to as Total Productive Maintenance (TPM ).
The determined by the PPS system optimal batch size is primarily dependent on the set-up time. This raises the question whether the established lot size is indeed optimal if a competitor convert the same investment in a fifth of the time and can produce a smaller batch size by 80 % more economical than its competitor.
The optimal batch size is one. To achieve it, one does not need a PPS system, but a setup strategy that makes it possible to manufacture small batches economically. Is it really useful to have millions in the construction of high-bay warehouses, in turn, cause the running costs, rather than be appropriately evaluated with a fraction of that amount the employee and to modify the systems umrüstfreundlich ( setup time reduction ). The method for doing this is called SMED. SMED stands for " Single Minute Exchange of Die ", so tool changing by the minute.
Qualification and Training of employees
Those who call for an increase in product quality, must first provide an improvement of process quality. Only if the employee register, that the management of their daily problems interested in the process and actively support in solving these problems, they realize that continuous process improvement is actually wanted.
Result orientation is demotivation. If the coach of the vaulters permanently raised the bar to 2.30 m and tells him how he can overcome this height, the jumper loses the fun of his sport - he resigned. Process-oriented management is supportive management.
In the Toyota factories, the workers are the most important factor in the process. It has been understood that the investment is the key competitive advantage in the qualification of employees, in the fight for quality and cost. Continuous process improvement is called continuous training of employees.
Toyota trains such as tape employees in specially designated training centers before they are used in real operations. For example, painters are trained with special water training facilities. On this one does this painting a car. The used water is collected and compared the target quantities. In addition, so-called Toyota certified Master Trainer who train and advise Toyota's coach. Training at Toyota are strongly focused on justifications, focus and repetition.
Continuous Improvement Process
As in politics, so also leads in the process planning, the fixation on the Great litter rather to a halt. The Innovationslastigkeit planning prevents the active participation of workers in shaping their jobs in many companies. The risky and expensive automation of complex activities taking cheap organizational improvement of processes any room.
This often prevents a bureaucratic proposal being that the number of suggestions is significantly increased. In German industry make 100 employees per year, about 60 proposals.
In the Toyota factories but a single employee makes an average of 62 suggestions per year.
Are you a ( any ) employees the opportunity to improve conditions in his own work, a considerable creative potential is released. At work, he is the expert - not the engineer who planned this work months or years ago. The staff is struggling with the daily problems and often wonders why so and not otherwise? Only through the participation of the workplace it is "His " work. Used for this purpose, for example, the 5-S method.
The aim is to motivate through training programs, group discussions and Kaizen workshops the staff to make suggestions for improving their jobs or processes. Kaizen the Japanese call this continuous improvement process. For this, there are at Toyota a detailed bonus system in which the instant gratification of suggestions for improvement is a top priority. The Toyota bonus system differs greatly from the company suggestion scheme in Germany.
Comparison with other systems and reception in the West
To a considerable degree of discipline among employees and a high standard of management and leadership will in the supervisor the Toyota Production System is work required. The Toyota production system of man and not the robot takes center stage. The production must be efficient, but the workers who produce the products that deserve respect and have the right to a meaningful task. The workers are not, as in many other factories, only those, who turn the screws, they are encouraged to reclaim everything they dislike about their workflow and make suggestions on how to improve processes. That is, the worker has to think about what he does in his work.
This is a serious difference to Henry Ford's production philosophy. There, the scope of work were so minimized that the worker did not have to think. There was only one motto and the name was " moving the sheet! " Toyota, however, has given his machine operators the ability to stop the assembly line if there is a problem and a lasting solution to the problem on the spot. Thus, it transfers to the worker on the band a significant amount of responsibility, which did not exist before.
The Toyota Production System (TPS) is recognized worldwide as the benchmark for highly efficient production in various industries. "Toyota is synonymous with consistency ," said Porsche ex- CEO Dr. Wendelin Wiedeking. He is an avowed admirer and imitator of the Toyota Production System. Toyota is in the eyes of many for cost and quality leadership and continuous improvement.
Although the TPS is described in detail in Western literature since the 1980s, an estimated more than 10 % of the companies are organized in Germany according to this principle today. In the automotive industry but now almost all automobile manufacturers and many suppliers have their own production system - usually along the lines of Toyota - developed and introduced. First German manufacturer was in 1992, the Adam Opel AG, followed Mercedes -Benz, MAN, Audi and Volkswagen. Even large suppliers, such as, for example, Robert Bosch GmbH, have successfully introduced its own production system in their business ventures.
The Toyota Production System not only works in large multinational companies, but can be successfully introduced in the middle class in a somewhat simplified form.
Evaluation of the method
The TPS method was examined on several occasions, and the results are significantly different. Some authors see the TPS as a method, others doubt this status.
" I believe did the Approaches Easily travel to other countries ... Japanese production and quality management works in non- Japanese settings. "
"I believe that the approach can be easily transferred to other countries ... Japanese production philosophy can be easily transferred to non- Japanese environments."
"The author Firmly Believes the Toyota production system can play a great role in the task for Improving the constitutions of American and European companies ... "
" The author firmly believes that the Toyota Production System can contribute a significant role in improving the state of the U.S. and European companies ... "
" Hall, in his Widely read JIT text, never even Questioned Whether JIT is a system, and proceeded to give detailed information on Implementing it through search steps as flow balancing, quality improvements, and setup reduction. "
" Hall, in his widespread JIT text, examined not even know if it was a system with JIT and went on to describe detailed introduction methods such as Flußausgleichen quality improvement and setup time. "
Robert H. Hayes did not reveal any particularly strong use of modern production technologies, quality circles or uniform pay systems. In their own words:
" ... No exotic, strikingly different Japanese way of doing things. "
" ... No exotic, obviously different Japanese way to address the matter. "
"The modern Japanese factory is not, as many Americans believe, a prototype of the factory of the future. If it were, it might also be, curiously, far less of a threat. We in the United States, with our technical ability and resources, ought then to be able to duplicate it. Instead, it is something much more difficult for us to copy; it is the factory of today running as it should. "
" The modern Japanese factory is not - as many Americans believe - the prototype of the factory of the future. Would this be correct, it could oddly enough, represent a much smaller threat. We in the United States, with our technical skills and resources should then be able to make it. Instead, it is something much more difficult to be copied: It is the factory of today, who is running as it should "
Many of these interpretations are attributed to the fact that the respective authors possessed at the time of their studies in the 1980s do not have complete information about the system. Ohno even admitted that a deliberately confusing terminology has been used to obscure the understanding ( Myers ( 1990) cited in Hopp, 1999). It has since shown that the TPS can also be adapted to the mentality of machine operators and corporate cultures in countries outside of Japan, or vice versa, the workers and Cultures at the TPS.
It crystallizes out that play a significant role in introducing the corporate culture ( the way we do things around here ) and the sometimes substantial changes. This also explains why Toyota took 50 years to reach the present condition and use only about 20 percent of companies in Japan the TPS. Obviously, it is difficult in Japan to achieve such a fundamental change.