optimization the availability of a system with short circuit and common cause ‎failures‎

Redundancy allocation problem is one of the most important problems in reliability field. in this problem, the reliability and availability of the systems are maximized via allocating redundant components to subsystems. many different assumptions are considered to draw this problem near to real conditions. in this paper, we work on a system with k-out-o-n subsystems as well as considering short circuit and common cause failures for the components in each subs in addition to ordinary components failures. obviously, the components are repairable. we present a markov model to show the effects of these two failures on system availability. for solving the presented model, we used biographic based optimization (bbo) algorithm and minimize the system cost to achieve the predetermined system availability. we used the bbo algorithm for calculating the availability of the system, and response surface methodology for tuning the algorithm parameters.