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Relations Between Safety and Productivity
Kazuaki Goto & Shingo Kato
*Assembly Dept., Tsutsumi Factory of Toyota Motor Co.*


1. Outline of Tsutusmi Works
Established: 1970 (28-year operation as a passenger car factory) Capacity: 400,000 - 500,000 cars per year The Number of Employees: 5,600 employees in the factory, including 1,500 employees working for the assembly department. The factory has been functioning as a mother plant of Toyota Kentucky factory in the USA and Derby factory in England since 1988.

2. Situation before the Factory Establishment up to 1970
All factories in Toyota performed in a similar way. Not only did productivity steadily develop, but also the number of problems in industrial accidents such as occupational injuries and diseases has sharply declined since 1960 (see Figure 1). Toyota's factories have taken many measures, sometimes guided by the government administration, sometimes to meet company demands, but we will leave it out here.
Listening to the name of Toyota Motor Co., not a few people may bear "Toyota Production System" (hereafter, TPS) in mind. Now let us review the system.
Toyota Motor Co. has promoted its operations based on the concept of Just in Time (hereafter, JIT) and JIDOUKA since it was established. As it is already known to you, JIT is a concept that necessary materials with necessary amount are available when they are needed on assembly operation, which marks high production efficiency with the minimum inventory. At the same time, the elimination of excessive stocks helps us create clean and open working environment, which is also effective to promote safety at work.
JIDOUKA means exactly the same as JIDOUKA which means "automation" in Japanese. However, our JIDOUKA uses a different character, and means "automation with human intelligence." It is an idea to eliminate wasteful works by minimizing defective products in order to keep the high productivity. It is realized by: stopping operation in the case of any trouble; keeping defective semi products from being supplied to the next process; and manufacturing products of good quality. At the same time, we can work more safely by eliminating irregular operations. We believe that productivity should be developed by improving a manufacturing mechanism based on such philosophy as "JIT" and "JIDOUKA", not by giving heavy pressure on employees.
Then, how can we provide safe and comfortable workplace in which employees can handle their works more smoothly? What is important for this ends is to standardize each individual's work to provide a system and working environment so that employees can operate the standardized work, that is "improvement." Besides, we recently have to challenge a new and difficult theme, i.e., how we let our employees feel that they lead a meaningful life.
In 1913, Ford Inc. successfully introduced the conveyor manufacturing system and realized an epoch-making productivity. A quarter of a century later, the system was introduced to Japan. Adopting the idea of "JIDOUKA," Toyota Motor Co. modified the system so that every employee could stop the conveyor. Here you see our wisdom to unite the two principles: friendly to employees and higher productivity.
We have promoted safety and health activities urged by the combination of government guidance and in-house needs since the end of the second world war, in particular. We observe that the success in safety and health activities have resulted in higher productivity. Based on the idea that occupational safety is the beginning and also the goal of work, our productivity improvement activities are always linked with safety and health activities.
"No production without safety." With the idea that safety is a basis of production and all other corporate activities, our executives started to take initiatives on safety and health activities since 1970. The activity currently has been developed to spiral improvement both executives and employees.

3. Situation After the Factory Establishment
Relations between occupational safety and productivity in Tsutsumi Woks have traced the same process as other Toyota factories (see figure 2).
As mentioned above, the number of occupational injuries in Japan has sharply declined. Due to counter taken to environment (machine, material, etc.) and employees, the number of accidents happened on regular work recently has reached almost zero. We have experienced no injuries in our factory for the past four years. However, we are suffering from injuries mainly happened in irregular work and relatively minor ones such as particles into eyes, careless fall, and a sprain.
In automobile industries, we have observed some changes in the kind of occupational safety and health problems: Ergonomics problems like musculo-skeletal disorder has been highlighted for a decade. It is believed that this is caused by mismatches between stress in assembly process and employees' stress-resistant ability, but we are still continuing to identify the case.
We are coping with this problem, for instance, by designing a vehicle which can be more easily assembled, or modifying work process to reduce the stress on the one hand. On the other, we are training our employees to improve their stress-resistant ability. It is discovered that this ability is largely related to individual's physical strength, but that trainings can help the recovery from stress to a certain degree. With an increasing number of aging and female employees joining this work, we think that this issue should be resolved by all means.
Now I believe you understand that safety and health is highly correlative to productivity, which is the main theme here. For better understanding, please see Table 1 on Toyota's corporate activities.
We believe that the success in business, i.e., high productivity and excellent safety and health performance, depends on how we effectively use resources such as people, materials and equipment. As Table 1 shows, measures taken by companies to make the best use of resources, human resource development, technical development and TPS, are effective not only for productivity or safety and health performance, but for all corporate activities. Toyota Motor Co. has developed corporate activities, with TPS in the center for a mechanism and management, in which human resources development and technical development have also been driven forward. Consequently, we keep an excellent level of safety, quality and production. We recognize that measures friendly for employees result in satisfactory management performance.
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