Stochastic redundancy allocation problem using simulation

Reliability is one of the main parameters of the products considered to be important to survive in the competitive market. Reliability in its simple form means the probability that a failure may not occur in a given period of time that is, the component performs adequately without failure. The subsystems or components in a system are arranged in series or parallel depending on the space constraint. However, the reliability of the system with components arranged in parallel is more than that system for which the components are arranged in series. Redundancy is the method of arranging the components in a subsystem in parallel such that if one component fails then the other component automatically comes into operation. Through redundancy, any desired level of reliability can be obtained, but in doing so, we have to invest money or other material resources to achieve the desired reliability. A designer has to consider the economic views of the organization in designing a system with high reliability. In this paper, a complex system (series-parallel system) is considered with stochastic reliability for its components. For a particular configuration, reliabilities of the components are generated and evaluated by the system reliability, after which simulation is run and repeated for various runs, before finally consolidating the configuration reliability and resource utilization. The simulation is carried for various feasible configurations and each configuration evaluated. The configuration with best reliability within resource restrictions is selected.