A MODIFIED BLOCK REPLACEMENT POLICY WITH 2 VARIABLES AND GENERAL RANDOM MINIMAL REPAIR COST

This paper considers a modified block replacement with two variables a nd general random minimal repair cost. Under such a policy, an operati ng system is preventively replaced by new ones at times kT(k=1, 2,) in dependently of its failure history. If the system fails in [(k-1)T, (k -1)T+T-0 it is either replaced by a new one or minimally repaired, and if in [(k-1)T+T-0, kT) it is either minimally repaired or remains ina ctive until the next planned replacement. The choice of these two poss ible actions is based on some random mechanism which is age-dependent. The cost of the ith minimal repair of the system at age gamma depends on the random part C(gamma) and the deterministic part c(i)(gamma). T he expected cost rate is obtained, using the results of renewal reward theory. The model with two variables is transformed into a model with one variable and the optimum policy is discussed.