AbstractIn engineering applications, many reliability systems can be modeled as k‐out‐of‐n systems with components having random weights. Before putting such kind of system into a working state, it is of great significance for a system designer to find out the optimal assembly of the random weights to the components. In this article, we investigate the performance levels of k‐out‐of‐n systems with random weights. Optimal assembly policies are obtained by maximizing the total capacity according to different criteria, including the usual stochastic order, the increasing convex [concave] order, and the expectation order. Based on the optimal assembly strategy derived by maximizing the expected total capacity, we further investigate stochastic properties of the resulting weighted system with respect to the vector of expectations of random weights. Numerical examples are provided to highlight our theoretical findings as well.
AbstractTaking repair action has proven to be an effective and flexible way to maintain the proper functioning of reliability systems. As a generalization of the minimal repair policy, the relevation is one of models for describing the repair effect. However, there are few studies in the literature dealing with the optimal allocation problem of repair resources to coherent systems because of their complex distribution theory. In this study, we tackle the allocation problem of a single relevation resource for coherent systems. Sufficient conditions based on the orderings among components lifetimes and repair effects are established for improving the system reliability by distinguishing the structural relationships of the minimal path/cut sets, which answer the problems proposed by Belzunce et al. Several numerical examples are also presented to illustrate the main results.