This thesis is concerned with an optimal repair-service rate of a joint service station for the standby redundant system consisting of two repairable units such as a main unit and a standby unit. The main unit is always in operation except when it fails. The standby unit is in service only for the duration of the main unit repair.
It is assumed that there is only one repair machine and the standby unit has a preempt in repair so that the repair of the main unit is interrupted whenever the standby unit fails.
System failures cause failure costs depending on system-down intervals, both the repair of the main unit and the repair of the standby unit are assumed to cause repair costs in proportional to the number of repair. In addition, the expense of repair machine is proportional to its repair rate.
From these cost informations, a long-run average expected cost function is derived using renewal theory. Then, a numerical example is treated to obtain the optimal repair rate by a search method, at which the long-run expected average cost is minimized.
