A new MVA-based approximation for closed queueing networks with a preemptive priority server

We propose a new MVA-based noniterative algorithm for solving closed queueing network models of computer systems with a preemptive priority server. The algorithm attempts to capture synchronization error, delay error, and the effect of preemption on the interarrival time variability of lower priority jobs at FCFS servers. The principal feature of our approximation is that it attempts to capture the effects of preemption not only at the priority server, but also at other servers in the system. Numerical results indicate that the algorithm predicts the performance measures of low priority jobs more accurately than previously developed MVA-based algorithms.