Designers for automation devices and machine tools need to have the abilities of self-assessing the degree of hazard for machinery during the designing stage. "Safety of machinery ‒ Principles of risk assessment" by ISO12100(JIS B9702) is a useful process tool designed to foster and improve designers' self-assessment abilities.

(1) Risk assessment

- Risk assessment refers to a series of logical approaches for evaluating the source of hazard associated with machinery using a statistical method.

- The risk assessment consists of the following two examinations:
  1) Risk analysis
  2) Risk evaluation

- Based on the result of risk assessment, measures for risk reduction will be implemented. Therefore, the risk assessment does not include "actions for risk reduction".

(2) Repetitive process for securing safety

A series of processes including risk analysis and assessment as well as risk reduction activities are repeated in the action process shown in the following figure. The knowledge on safety during the machinery design/production stage can be accumulated as a result.

*Note 1 --- Consider the operator's characteristics such as age, dominant hand, limit on physical performance, knowledge level (beginner or expert), etc.