Mission performance analysis of phased-mission systems with cross-phase competing failures

Phased-mission systems (PMSs) with sophisticated failure modes could behave diverse mission performance levels. The non-negligible competing failures, resulting from complicated components' failure patterns, have posed a great challenge for the mission performance analysis of PMSs. Even though many methods have been developed to facilitate reliability assessment of PMSs with competing failures in the past few decades, the mission performance analysis of PMSs with competing failures, varying from phase to phase, is still in difficulty. This feature is defined as the cross-phase competing failure, characterized by a two-by-two crossover combination of three or more failure modes in distinct mission phases. In this study, mission performance analysis of PMSs with cross-phase competing failures is conducted. By the divide-and-conquer strategy, the conditional probability of paths, resulting from the phase-dependent effects of components, is computed via an iterative method. Based on the phase equivalent binary decision diagrams, the mission performance analysis of PMSs with cross-phase competing failures is conducted. The probability distribution of mission performance levels, together with the system reliability, is assessed phase-by-phase based on the lifetime distributions of components and mission durations. A distributed multi-sensor multi-target tracking system, along with a set of comparative studies, is given to demonstrate the effectiveness and applicability of the proposed method. The results show that the proposed approach to mission performance analysis of PMSs is more computationally efficient than the existing combinational models.