The Toyota Production System – the methods

On the 4th International Conference for Production Research in Tokyo (1978), the department “production control” of Toyota presented the “in-house” made Toyota production system. In the following time a true migration of peoples started coming from the Atlantic countries going to Japan, which contributed to Toyota’s internal opinion that leaders are so named because they must lead managerial staff through production permanently.

The article has the title “Toyota Production System and Kanban System” and the subtitle “production on demand and humanization.” The Japanese authors worked out that the trigger for the new system was the realization that “the Japanese industry must do everything in their power to produce better quality goods with a higher degree of refinement and lower production costs than comparable countries.”

The outline of this paper is very informative:

1 the starting point of the concept – To make the best of the Japanese situation
2 Toyota Production System and its basic concept
2.1. Cost reduction by thoroughly eliminating waste
2.2. Full use of the skills of the workforce
3 Kanban System
3.1. The goal of the Kanban system
3.2. Description of the Kanban system
3.3. Notable points of the effect of the Kanban system
4 Extension of the “production on demand time when needed” by reducing set-up times of pressing tools
5 The result = the current situation at Toyota

“Kan Ban” and “expansion of production on demand time” are not listed under the heading “Toyota Production System”, but as separate sections. Obviously, these points are not considered to be necessary components of the TPS. We will come back to this point later.

In Section 2 of the report, the goal of the Toyota Production System and of all other production systems is defined and proven, which essential features are highlighted to achieve the goal, which means, elimination of waste and to use (to promote) the skills of the employees.

One characteristic demand of the TPS for the elimination of waste (muda) is translated with the word “trash” in the English version. The Japanese term “muda” just like the English term “waste” can mean both “trash” and “waste”. Today the clearly translation would probably be “waste” in conjunction with TPS.

Indeed, the “elimination of waste” is defined as an essential basis to achieve the objective, is written in the article, and the exposed features are only methods to reduce waste.

In the strict sense “waste” means, any use of resources that do not serve to increase the value of the produced goods.

To avoid possible objections: of course, this is a reflection of the market value and not an ethical value. The goal of a business is to create goods for the market, which means to cover the demand of the people for goods.

Waste exists, for example, by wasteful use of machinery and equipment, materials, human labour, tools and equipment, but also due to unnecessary storage of products.
A key finding (and proven in section 2.2 of the Toyota report) is that these goals can only be achieved

when employees see and understand the meaning of these activities and when they start working actively to use their knowledge and skills for avoiding waste.

The requirement for humanisation of work derives as a result.

It is reflected in the participation of employees in the design of work processes, job design, automation of dull, tedious and dirty work steps and not at least in the constant demand for improvement. This is fostered by the refusal of many young Japanese to work in the automotive industry because the work is seen as “dirty, noisy, stressful and boring”.

Another consequence of the requirement of avoiding waste is to reduce the stock. Traditionally this stands in contrast to the demand for high deliverability. The high delivery capability is required for the production when needed or just in time. But this requieres a high reliability of production, having high quality and fast response. The requirement of fast response results in the need of short setup times that can only be realized through the combined experience in working groups of several employees. The shorter set-up times (often feasible reductions to less than 50% of the previous effort) bring a better utilization of the facilities.

Also rework is waste. Rework can be avoided if errors are detected as early as possible, and if the design and installation of the product is made in a way so that human error and the installation of defective parts can be extensively avoided. Also this is achieved best when

  • the quality has become a high standard, which has spared the rework,
  • employees are actively involved in the design of the product and the assembly to share their knowledge about the causes of rework and the ways how to avoid them
  • subsequent delivery is possible by replacing faulty parts without delay

The goal to reduce the workload throughout the operation, including the management and control is not complete by the above mentioned types of waste.

A essential key element is to avoid all activities that are not necessary for the production of the products. This includes statistics that do not serve the power control and the incentive of control measures that can be easily performed by the employees in the workplace, etc.

To achieve the objectives in the best way, it is useful to make use of the knowledge of the employees. But in this case, the employee must feel that their contribution is recognized as a performance and he must be sure that he will not face disadvantages, but advantages resulting from the reduction of the effort.

The recognition of the employee as an substantial part of the company when he presents his work into the service of the company, is an important characteristic of the Toyota Production System.

According to many representatives of the school of the TPS, is the characteristic, to automate optimal assignment of staff operations that are repeated frequently, that are dirty or strenuous. Thus the efforts of employees to improve processes should be strengthened. But this is really just a method.

All of these goals overlap and form a network of factors, to take into account the conditions for their attainment is an essential element of the TPS. Even if you want to achieve some objectives by TPS, you have to work on and take these relationships into account.

Now we come back to the above-mentioned conspicuousness that two points are listed separately.

Generally the opinion comes up, that applying the methods developed in the context of the TPS has a result in the Toyota Production System. In fact, several methods have been developed with the TPS.

The best known are:

  • KAN BAN make production when needed, establishing reduction of material in production and detection of faults in the material flow and thus also the reduction of stocks,
  • VV-being, to promote the skills, the experience and the creativity of the employees thus to reduce waste and to improve production processes
  • Management by View to visualize faults in the material flow,
  • Quality circles to use the skills and experience of staff in resolving problems,
  • Yoke Poka to reduce defects and mistakes,
  • Jidoka to discover faults right in time (to raise awareness) and thus to avoid waste, etc.

But the application of these methods is not a prerequisite for the Toyota Production System. The important point is that the objectives above need to be achieved. Therefor you can often take the advantage of the known methods, but also develop your own, possibly even more effective methods. Especially if TPS will be introduced in a company that does not belong to the automotive, it is advisable to examine the methods, known for their possible application in-house very critically. Of course, quality circles, management by View and Poka Yoke can be applied in almost any operation, but KAN BAN is restricted within the company, for example in the production of composite parts. For services such as construction, it is not always useful.

In summary it can be stated that the methods do not build the Toyota production system, but the goals and the derived conclusions.

manufactus GmbH in cooperation with Mr. Helmuth Gienke

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