It is a manufacturing system developed by Toyota in Japan after World War II, which aims to increase production capacity by the elimination of waste. The Toyota Service Tools was invented and built to work by Taichi Ohno. Analyzing the problems inside the manufacturing environment; Ohno concluded that various types of waste are the main reason for inefficiency and low productivity. Ohio identified waste in many forms, including overproduction, waiting times, transportation problems, inefficient processing, inventory, and defective products.
Figure 1 shows the Toyota production system in detail. From this figure, it can be seen that TPS is not only a set of different tools, but it is the philosophy and integration of various devices and systems to achieve a common goal of reducing waste and improving efficiency. Each element of this house is important, but more important is the way the elements reinforce each other. Just in time (JIT) means the removal of inventory used to act against problems arising in production. The idea of a one-piece flow is to create a unit at the rate of customer demand or tack time. Using smaller buffers means that problems such as quality defects are immediately visible. This reinforces Jidoka, which stops the production process. This means that workers will have to solve problems quickly and immediately to resume production.
Sustainability is at the foundation of the house. There is a problem when working with small inventories and stopping production which causes instability and a sense of urgency among workers. In mass production, when a machine goes down, there is no sense of urgency as the maintenance department is determined to fix it while the inventory continues to operate. Conversely, in lean production, when an operator shuts down equipment to fix a problem, other operations will also stop immediately, with no crisis occurring. Hence the urge for everyone in production to fix the machine in working conditions and to fix the problems to run the production as soon as possible.
If the same problem occurs repeatedly, management will quickly conclude that it is an important condition and should be torn without delay. People are at the center of the house because it is only through continuous improvement that the operation can ever achieve this necessary stability. People should be trained to look at waste and solve the root causes of the problem by repeatedly asking why the problem occurs. The problem-solving should be at the actual site of the problem where everything is visible and also practical; This problem-solving technique is called Genchi Genbutsu. In general, TPS is not a toolkit. It is not just a set of lean tools like in-time, cell, 5S (sort, stabilize, shine, standardize), kanban, etc. It is a sophisticated system of production in which all parts contribute to a whole. Overall, its focus is on continuously improving and encouraging the people on the processes on which they work.