A SUMMARY OF PERIODIC REPLACEMENT WITH MINIMAL REPAIR AT FAILURE

Abstract

Several periodic replacement policies with minimal repair at failures are summarized: 1) A policy for a unit with random and wearout failures. 2) Two modified policies where if a failure occurs just before the replacement time, then (i) a unit remains failed, (ii) a unit is replaced by a new one. 3) Three imperfect preventive maintenance (pm) policies where (i) a unit after pm has the same failure rate as before pm with a certain probability, (ii) the age of a unit becomes x units of time younger at pm, (iii) the age of a unit after pm reduces to at at pm. Expected cost rates for each model are obtained and optimum policies are discussed. Some examples for the above models are presented.