Document Type : Research Paper


Aerospace Research Institute, Ministry of Science, Research and Technology, Tehran, Iran


The reliability of manufacturing systems modeling and analysis is a complex process. Usually, their behavior is similar to multi-state systems. The configurations of such systems, possibly with load sharing and other structural dependencies, are designed to provide high reliability/availability. Consequently, this scheme can help companies to improve efficiency and reduce operating costs. Maintenance and part replacement are implemented during operation and utilization to keep their performance. Decision-making about spare ordering is difficult because of the interconnection between spare parts inventory and maintenance strategy. In this paper, the characteristic parameters of spare parts inventory management and maintenance policies are jointly considered for multi-machine systems (manufacturing systems) with different types of dependencies among them (economic, load-sharing, and multi-state configuration). Two maintenance policies are considered: condition-based and preventive maintenance. The interactions between maintenance policies and spare parts management are considered for determining a manufacturing system’s cost and availability. The influence of these factors is investigated. Load sharing factor and ordering time are more important, and their influence is higher than others.

Graphical Abstract

Reliability, availability, and maintainability modeling of multi-state systems with load-sharing structure


Main Subjects