Title:Optimal parameters of the degrading unit with state-dependent repair timeAuthor(s):Dmitry EfrosininAbstract:In this paper we study a degrading unit subject to gradual and instantaneous failures. A death process with observable states describes occurrence of the gradual failures. The unit fails completely upon departure from the last failure state or after an instantaneous failure. The repair time depends on the failure state where the unit comes from. The unit is supplied by a controller who can trace the system states. Based on this information the controller generates a signal about future instantaneous failures. The control problem consists in evaluation of the optimal number of degrading states and of the index of a signal state. It is studied mainly in a stationary regime for unit of multiple use when the average cost function per unit of time is expressed as a ratio of expectations.Publishing:7/2013