Process of Judgment Error on Collision Risk by Modeling Judgment Patterns of Officers

The purposes of marine accident analysis are to find out the cause and safety measures of marine accidents and to evaluate the effectiveness of the measures. Many marine accidents are considered to be due to human factors. Experiments with bridge simulators are effective for analyzing human factors in ship operation. Analytical approaches to some accidents with bridge simulators have already been carried out. However, analytical method has not been established yet. In our previous paper [1], as the first phase of analysis, we proposed a method to identify the most important task (bottle neck task) in the accident process. As a result of experiments and analysis of a collision accident, “Judgment” was identified as the bottle neck task for preventing collisions. However, in order to identify the primary cause of the accident, it is necessary to know the process of judgment error (background) of the accident. In this paper, as the second phase for analysis, process of judgment error in the collision accident is made clear by modeling judgment pattern of officers. From the result, two-stage judgment error is identified as the primary cause of the collision.