Reliability allocation multi-objective optimization for products under warranty

Generally, the goal of reliability allocation is to maximize product reliability under various physical or budgetary constraints, and to minimize cost subject to reliability or physical constraints. For products sold with warranty, the product reliability affects not only the manufacturing cost but also the warranty servicing cost. Thus the reliability allocation decision can be regarded as a multi-objective optimization problem and must consider these costs for products under warranty. This paper develops a general multi-objective model considering above factors. To obtain the optimal reliability allocation for engineering systems, the multi-objective evolutionary algorithm NSGA-II is adopted to obtain a Pareto optimal solution set. Then the final representative solutions for the reliability allocation problem can be chosen from the Pareto solution set. Finally, a numerical example is given to illustrate the proposed method.