Mission abort in asynchronous redundant systems under multi-type shocks

Mission abort policy (MAP) has been widely studied in systems subject to random shocks. Most existing models assume either individual shocks degrading a single component or common shocks simultaneously impacting multiple components. A few recent studies address both types of shock processes, but are limited by restrictions on the timing of abort decisions. In this paper, we relax these timing restrictions by allowing aborting decisions to be made at any time during a mission performed by an asynchronous system with two heterogeneous components, offering more responsive decision-making. A new probabilistic modeling procedure is proposed for deriving the mission success probability and the expected cost of component losses, which are further used for calculating the normalized expected damage (NED). The optimal MAP that minimizes NED is then determined. A bi-sensor monitoring system is analyzed to illustrate the proposed model accommodating both individual and common shocks as well as flexible abort decision timing.