Rapid improvement of stochastic networks using two-moment approximations

This paper investigates a method for rapidly improving the performance of stochastic networks. The method uses queueing network techniques based on parametric decomposition and two-moment approximations. It employs some recently devised developments to the approximations, especially in the context of closed queueing networks with synchronization stations. We describe these developments and explain how the method uses them. It appears to offer a substantial advantage in speed, and reduces the dependence on repetitive simulation runs for identifying opportunities to improve network performance. We present an example from airfield operations, in which the method evaluates the tradeoffs with respect to several strategies for enhancing airfield performance, such as the introduction of concurrent operations, the reduction of service variability, and the increase in airfield capacity.