ON ASSESSING OPERATOR RESPONSE-TIME IN HUMAN RELIABILITY-ANALYSIS (HRA) USING A POSSIBILISTIC FUZZY REGRESSION-MODEL

Operator response times for off-normal events in nuclear power plants have been used to assess human failure probabilities. Usually, log-nor mal distribution is applied to the relation of response times and fail ure probabilities. In the literature there have been several studies o n estimating the response times. Since the response times are affected by the performance shaping factors, a regression model can be applied to estimate the response times. The conventional regression model reg ards the deviations between the observed and estimated values as measu rement errors. However, the deviations of the dependent variable, the response times can be dependent upon the fuzziness of the parameters f or the independent variables, the performance shaping factors. In this research, possibilistic linear regression models have been used to as sess fuzzy parameters and furthermore response times associated with t he performance shaping factors. (C) 1996 Elsevier Science Limited.