Abstract: This study presents a transient analysis and performance evaluation of a two-class repairable machining system incorporating priority repair discipline and shared spare units. The system is modeled using a continuous-time Markov chain (CTMC) framework to capture the stochastic nature of machine failures and repairs. Two distinct machine classes are considered: Class-1 (high priority) and Class-2 (low priority), where Class-1 failures receive preemptive service priority. The model accounts for limited repairmen and a finite pool of spares shared among machines, which makes it highly relevant to realistic manufacturing environments. By deriving and solving a set of transient state differential equations, important reliability and availability metrics such as expected number of failures, system availability, and throughput are obtained through a matrix exponential solution approach. Numerical analysis demonstrates that increasing the number of repairmen or spares significantly enhances system performance, while higher machine failure rates adversely affect availability. The findings provide valuable insights for designing optimal maintenance policies that balance repair capacity, spare provisioning, and operational cost to ensure high system reliability and productivity.

Keywords: Reliability, Availability, Queueing Model, Continuous-Time Markov Chain (CTMC), Transient Analysis, Priority Repair, Shared Spares, Manufacturing Systems, Matrix Exponential Solution

Downloads: | DOI: 10.17148/IARJSET.2024.114112