Optimal aborting rule in multi-attempt missions performed by multicomponent systems

When the risk of a system's failure during a mission increases with time, it may be reasonable to abort a mission and to attempt it again after the corresponding rescue procedures. This risk can increase with time either when a system's lifetime is characterized by the increasing failure rate, or due to a hostile environment. In this paper, a random environment is modeled by the point process of shocks. Each shock increases the failure probability, thus exhibiting the aging effect. We generalize some recent results reported in the literature to the multi-attempt case when each of statistically identical system's components can independently complete a mission. The corresponding probabilistic model is developed and the tradeoff between a mission success probability and the expected number of lost components is discussed. The problem of minimization of the overall expected operational losses is formulated. Different types of abort policies have been compared in the detailed illustrative example. It was shown that the smallest expected operational losses can be achieved when the mission abort rule depends on the number of an attempt and on the number of components starting this attempt. (C) 2019 Elsevier B.V. All rights reserved.