Optimizing Reliability of Parallel Systems: Prioritized Preventive Maintenance and Inspection

The present study focuses on enhancing the reliability of a system comprising two identical units operating in parallel. Initially, both units are in operative mode. A single serviceman is available to perform all repair activities. Upon failure, a unit undergoes inspection to determine if it is repairable. If repairable, the unit is repaired by the serviceman; otherwise, it is replaced with a new unit. Preventive maintenance is conducted after a specified maximum operation time, with priority given to preventive maintenance over repair activities. Mathematical expressions for various reliability measures, such as Mean Time to System Failure (MTSF), availability, and profit analysis, are derived using the semi-Markov process and regenerative point technique. Tables and graphs are provided to visualize the efficiency of the model. The main contribution of this paper is to provide system designers with insights on how to enhance the profitability of parallel systems by implementing a priority-based approach.