Instantaneous availability of a single-unit non-markov repair time omission

This paper introduces a new model for a single-unit non-Markov repairable system in which the repair time is sufficiently short (less than some given critical value); it won´t result in system failures. Such short repair interval can be omitted from the downtime record. In this paper the critical repair time is considered into two classes, one is a constant and the other is a non-negative random variable. Then the availability for the new model is calculated. Finally, some numerical examples are given to illustrate the proposed model.