Since the products are subjected to varying stresses in the strength of the product and the stress that the product withstands, then its reliability must be estimated using stress-strength analysis. Unfortunately, when both stress and strength follow Weibull behavior with different shape parameters, there is no closed solution in reliability estimation. Therefore, in this paper, the formulation for performing Weibull stress-resistance analysis with different shape parameter is presented. In addition, the formulation to determine the probabilistic safety factor corresponding to the product is given. And since the relationship between the safety factor and reliability are unique, then, the reliability is random and the safety factor is random.
