COST ANALYSIS OF THE MACHINE-REPAIR PROBLEM WITH R NONRELIABLE SERVICE STATIONS

This paper studies the machine-repair problem with N operating machine s and R non-reliable service stations under steady-state conditions. T wo different types of service stations are considered. In type 1, each service station serves at an identical service rate, while in type 2, each service station serves either at a slow rate or at a fast rate. Failure and service times of the machines, and breakdown and repair ti mes of the service stations are assumed to follow a negative exponenti al distribution. Matrix geometric theory is used to find the steady-st ate probabilities. A cost model is developed to obtain the optimal num ber of service stations for both types. Under the optimal operating co nditions, several system characteristics are evaluated for both types.