Estimating Human Error Probability using a modified CREAM

Human Error Probability (HEP) point estimation is important for Probabilistic Safety Assessment (PSA) of socio-technical systems. We present a modified basic method of CREAM to provide the point estimation of HEP for PSA. Five acknowledged assumptions are introduced firstly and the HEP point estimation formula is elicited based on them. Furthermore, the reasonability of the method is discussed and the consistency with other two benchmarking HRA methods, THERP and HEART is validated. Finally, a simple example about starting up the submarine's engine is introduced and the probability of the error forgetting the warm operation is calculated using the modified method. The result of the method is consistent with the recorded human performance data and THERP.