Abstract
In the work site, various automated manufacturing machines are used. As a result, laborers are released from heavy line labor and labor in harmful environments. However, many industrial accidents are generated by automated manufacturing machines. This paper considers the viewpoint of accident prevention in the operation of automated manufacturing machines. There are operations where a delay cannot be permitted and operations where hurried work cannot be permitted. Therefore, the operation button has a color and shape suited to the operation. This characteristic is presented as being evaluated as an "asymmetric property on the time axis." For a laborer to accept mechanical risk, it is necessary that the degree of harm be sufficiently small or that avoidance of the danger be easy. When the "asymmetric property on the time axis" becomes high, mechanical safety improves. This makes it easy for the laborer to accept the machine.
