Eryilmaz, SerkanIndustrial Engineering2024-07-052024-07-052021120377-22171872-686010.1016/j.ejor.2021.03.0072-s2.0-85106247335https://doi.org/10.1016/j.ejor.2021.03.007https://hdl.handle.net/20.500.14411/2002For a system (or unit) whose lifetime is measured by the number cycles, according to the discrete time age replacement policy, it is replaced preventively after n cycles or correctively at failure, whichever oc-curs first. In this paper, discrete time age replacement policy is revisited when the lifetime of the system is modeled by a discrete phase-type distribution. In particular, the necessary conditions for the unique and finite replacement cycle which minimizes the expected cost per unit of time are obtained. The nec-essary conditions are mainly based on the behavior of the hazard rate. The results are illustrated for some special discrete phase-type lifetime distributions. Computational results are also presented for the optimal replacement cycle under specific real life setups. (c) 2021 Elsevier B.V. All rights reserved.eninfo:eu-repo/semantics/closedAccessReliabilityAge replacementHazard ratePhase-type distributionArticleQ12952699704WOS:000668929800021