Abstract
•System with production unit and multiple storage units is considered.•The storage units are failure prone and operate in parallel.•The mission fails if neither production unit nor storage can supply a demand.•Algorithm for evaluating the mission success probability is suggested.•Illustrative example of system analysis is presented.
Despite the crucial role of product storage played in the operation of real-world systems, only very few reliability studies have considered this component in the system reliability modeling and analysis and the existing models assume only a single storage unit per system or subsystem. This paper makes advancements by modeling an unrepairable system with a production unit (PU) and multiple parallel storage units (SUs) of limited capacity. Both the PU and SUs are failure prone or imperfect with time-to-failure following arbitrary distributions. The surplus product in the case of the PU's performance exceeding the demand is evenly distributed among available SUs. The cumulated products in available SUs may subsequently compensate the deficiency when the PU fails or has insufficient performance. We put forward a numerical algorithm of evaluating the mission success probability (MSP) of the considered system with required demand and mission time. We conduct a case study on a water supply system with five SUs to illustrate the proposed model and investigate impacts of several model parameters (including initial SU filling, SU capacity, the number of SUs, PU productivity, reliabilities of PU and SU) as well as their interactions on the MSP.