Abstract
We consider a planned maintenance policy of providing identical spares successively for replacement of a failed unit as corrective maintenance or a non-failed unit as preventive maintenance. We assume that an identical spare is provided by order with a lead time. Then we consider when we should order an identical spare to minimize the expected cost per unit time in the steady state. In particular, we take into account the salvage cost for the non-failed unit. We show that there exists an optimum ordering policy under certain conditions.