Control Variate Models for Estimating Transient Performance Measures in Repairable Item Systems

We develop a new modeling idea for comparing infinite-source, ample-server models (\infty /\infty ) and finite-source, finite-server models (f/f). The comparison provides an efficient estimate of the error when approximating an f/f system with an \infty /\infty system and allows the analytical solution of the \infty /\infty model to be used as a control variate. We show that using \infty /\infty models as control variates for f/f systems can be an effective variance reduction technique for system performance estimates. Using these estimates will allow us to determine more efficiently when \infty /\infty models are good approximations for f/f systems.