A Proposal for Operator Team Behavior Model and Operator's Thinking Mechanism

Operating environment in huge systems like nuclear power plants or airplanes is changing rapidly with the advance of computer technology. It is necessary to elucidate thinking process of operators and decision-making process of an operator team in abnormal situations, in order to prevent human errors under such environment. The Central Research Institute of Electric Power Industry is promoting a research project to establish human error prevention countermeasures by modeling and simulating the thinking process of operators and decision-making process of an operator team. In the previous paper, application of multilevel flow modeling was proposed to a mental model which conducts future prediction and cause identification, and the characteristics were verified by experienced plant operators. In this paper, an operator team behavior model and a fundamental operator's thinking mechanism especially “situation understanding” are proposed, and the proposals are evaluated by experiments using a fullscale simulator. The results reveal that some assumptions such as “communication is done between a leader and a follower” are almost appropriate and that the situation understanding can be represented by “probable candidates for cause, determination of a parameter which changes when an event occures, determination of parameters which are influenced by the change of the previous parameter, determination of a principal parameter and future prediction of the principal parameter”.