(A) periodic replacement policy with minimal repair cost limit

Abstract

This thesis is concerned with a periodic replacement policy with a minimal repair cost limit. Replacement policies with minimal repair have been proposed under the assumption of a constant minimal repair cost. In real situations, however, the cost varies randomly. Thus a periodic replacement with a minimal repair cost limit is proposed. When a system is to be repaired, it is first inspected and the repair cost is estimated. Minimal repair is then undertaken if the estimated cost is less than a predetermined minimal repair cost limit L. Otherwise, the system is replaced Replacement is also made if the system fails for the first time after age T. The average cost rate is used as a criterion and its behaviors are examined. Numerical comparison with other replacement policies is also made under the assumptions that the time to failure follows a weibull distribution and repair cost an exponential distribution and the proposed policy turned out to be superior to existing replacement policies with minimal repair.