Simulation Algorithms to Assess the Impact of Aging on the Reliability of Standby Systems with Switching Failures

We analyze the influence of aging on the reliability of a two-component standby system with switching failures (2SBSF). When the backup component is aging in standby as if it is working, we have a 2SBSF with full aging. Typically, such a system is modelled with a rate diagram (where the failure rates are time-dependent) which has an adjacent system of 3 ordinary differential equations (ODEs). The reliability characteristics of the 2SBSF with full aging can be obtained from the numerical solution of the formulated Cauchy problem. Alternatively, simulation modelling can produce the same results, but without using the rate diagram. In that way we can adapt the simulation algorithms to treat the cases when either the backup component does not age in standby (2SBSF with no aging), or when the backup component ages in standby slower than in operation (2SBSF with partial aging). In the last two cases there is neither rate diagram, nor a system of ODEs since the 2SBSF is not state dependent when the full aging assumption does not hold. We develop ten algorithms to facilitate the simulation solutions of the 2SBSF with no aging and with partial aging. We emphasize on the ways to deal with the numerical problems created by working with truncated distributions and with random sampling