A Simulator for Human Error Probability Analysis (SHERPA)

• We propose a new method for Human Reliability Analysis called SHERPA.
• SHERPA is able to model human behaviour and to predict the error probability.
• Human reliability is function of task done, influencing factors and time worked.
• SHERPA exploits benefits of the simulation tools and the traditional HRA methods.
• SHERPA is implemented as a simulation template enable to assess human reliability.

A new Human Reliability Analysis (HRA) method is presented in this paper. The Simulator for Human Error Probability Analysis (SHERPA) model provides a theoretical framework that exploits the advantages of the simulation tools and the traditional HRA methods in order to model human behaviour and to predict the error probability for a given scenario in every kind of industrial system. Human reliability is estimated as function of the performed task, the Performance Shaping Factors (PSF) and the time worked, with the purpose of considering how reliability depends not only on the task and working context, but also on the time that the operator has already spent on the work. The model is able to estimate human reliability; to assess the effects due to different human reliability levels through evaluation of tasks performed more or less correctly; and to assess the impact of context via PSFs. SHERPA also provides the possibility of determining the optimal configuration of breaks. Through a methodology that uses assessments of an economic nature, it allows identification of the conditions required for the suspension of work in the shift for the operator׳s psychophysical recovery and then for the restoration of acceptable values of reliability.