Efficient simulation of the National Airspace System

The National Airspace System (NAS) is a large and complicated system. Detailed simulation models of the NAS are generally quite slow, so it can be difficult to obtain statistically valid samples from such models. This paper presents two methods for reducing the complexity of such networks to improve simulation time. One method is removal of low-utilization queues - that is, replacing a queueing node with a delay node, so that airplanes experience a service time at the node but no queueing time. The other is removal of nodes by clustering - that is, where groups of nodes are collapsed into a single node. We employ the methods on simple networks and show that the reductions yield very little loss in modeling accuracy. We provide some estimates for the potential speedup in simulation time when using the methods on large networks.