Efficient reliability analysis of dynamic k-out-of-n heterogeneous phased-mission systems

In this paper, an efficient analytical modeling method is proposed for reliability analysis of k-out-of-n phased-mission systems (PMSs). A PMS is a system involving multiple, consecutive and non-overlapping phases of tasks during its mission, which abounds in complex technological systems such as aerospace systems, nuclear power plants, and high-performance computing systems. Due to dynamics in the system configuration and component behavior as well as statistical dependences across phases, exact reliability evaluation of a PMS is a time-consuming and complicated task. This paper proposes a new efficient multi-valued decision diagram (MDD) based method for the reliability analysis of a special class of non-repairable PMSs called k-out-of-n PMS where the same number of components n is involved in all the phases but the required number of working components k may vary from phase to phase. Particularly, a new MDD generation method is proposed for a fast construction of the PMS MDD model. The system components are not necessarily identical; they can be heterogeneous in their failure time distributions. Examples are provided to demonstrate the application and advantages of the proposed methodology.