Recent Empirical Studies on Influential Factors in the Diagnosis Reliability of Operators

A diagnosis, which implies the identification of the most plausible causes of off-normal events, has been recognized as an important task for securing system safety. Many HRA (human reliability analysis methods have thus presented the models to quantify the human error probability (HEP) of a diagnosis. In this paper, we reviewed the influential factors considered in the HRA methods and examined the findings of recent empirical studies. Based on the findings of empirical results, the implementation of traditional HRA methods is discussed. The time required is the most influential factor in the diagnosis HEP; however, the THERP and ASEP methods allow an adjustment of the diagnosis HEP based on training experience or task familiarity. Because deriving concrete findings from empirical data requires lots of samples and results in various environments, it is necessary to be careful when concluding the influential factors in terms of diagnosis reliability. The definition of a diagnosis can be differently interpreted according to the purpose of HRA research and applications.