 The reliability of a product can be determined by analyzing its stress strength characteristics. However, if the stress and strength follow different Weibull distributions with different shape parameters, it becomes difficult to find a close solution for the reliability stress strength. In this paper, we derive a formula to analyze the reliability stress strength with different shape parameters, as well as a formula to calculate the corresponding safety factor. Because the relationship between the derived safety factor and the designed reliability is unique, the reliability is therefore random. This article was authored by Manuel Barrow, Manuel Roman Pena Menárez, and Baldomero Villa.