Incorporating Distribution Parameter Uncertainty in Reliability Calculation

Probabilistic methods for risk and reliability assessment require knowledge of statistical variation of design parameters. Often the parameters themselves are uncertain. In such cases it is important to understand how parameter uncertainties will affect the reliability measures, probability of failure or reliability index calculations. This article presents the different methods that have been developed to calculate sensitivities of reliability index (beta) or probability of failure (P_f) to the distribution parameters. Different point and interval estimates for reliability measures in the presence of parameter uncertainty are discussed.