Mehdi Zarabian - Department of Industrial Engineering, Islamic Azad University, Qazvin Branch, Qazvin, Iran
Seyed Taghi Akhavan Niaki - Department of Industrial Engineering, Sharif University of Technology, Tehran, Iran

Abstract— This paper involves developing a new model for the multi-state redundancy allocation problem of seriesparallel systems. The system consists of subsystems in series, where components are used in parallel for each subsystem. There are various types of components as candidates for allocation. These components are characterized by their cost, weight, and reliability. Besides, they have various levels of performance ranging from functioning perfectly to fail completely. The aim is to find the redundancy that minimizes the cost while maximizes the reliability. A NSGAII algorithm is used to solve the multi-objective problem, where the universal generating function for multi state components is used to obtain the reliability of a given system. In addition, a penalty function that encourages the solution algorithm to explore within infeasible solutions is proposed. At the end, a numerical example is used to validate the solution and to assess the performance of the proposed methodology under different configurations.

Reliability; Redundancy allocation problem; Multi-State; Universal Generating Function