| Abstract: | In this paper we deal with an optimum ordering policy for a one-unit system with a general lifetime, where the failed unit is scrapped without repair. A spare can only be provided after a lead time. Two kinds of orders (regular and emergency) are possible, each having a different, generally distributed lead time. Weather conditions are subject to a Markov process with two states-normal and abnormal which has a constant rate λ from normal to abnormal weather condition and μ from abnormal to normal respectively. The operational status of the unit is affected by the abnormal weather condition. The costs include downtimes, salvage, penalty, ordering costs. The optimal policy discussed is the one which maximizes the cost effectiveness, and is illustrated with a numerical example |
