Transient Analysis of Multistage Degraded Systems with L Exponential Failure Modes and Partial Repair Times Modeled by Coxian-2 Distribution

Abstract. The paper presents a model of multistage degraded system subject to L random failure modes and partial repairs. A transient analysis is performed and transient probabilities are calculated to find the availability, the mean of life times and of operational life times. Constant state dependent transition rates for the degradation process as well as for the failure process are considered. In contrast, the state dependent partial repair times follow distributions with the square of coefficient of variation greater than or equal to one. Moreover, the special case of Coxian-2 distributions for the partial repair times is investigated. A numerical example is provided to illustrate applicability of the expressions that are obtained throughout the paper.