Analysis of Discrete-Time Machine Repair Problem with Two Removable Servers Under Triadic Policy

This paper analyzes a controllable discrete-time machine repair problem with L operating machines and two repairmen. The number of working servers can be adjusted depending on the number of failed machines in the system one at a time at machine''s failure or at service completion epochs. Analytical closed-form solutions of the stationary probabilities of the number of failed machines in the system are obtained. We develop the total expected cost function per machine per unit time and obtain the optimal operating policy and the optimal service rate at minimum cost using quadratic ¯t search method and simulated annealing method. Various performance measures along with numerical results to illustrate the in uence of various parameters on the bu®er behavior are also presented.