AbstractMilitary communications networks are large complex systems; their physical dynamics, composition, workload characteristics and operational goals make them very hard to model and analyse. It is particularly difficult to build a generalized model that can adequately fit each instance, generate a workload that exercises the network in a realistic way, and measure network effectiveness in terms of the operational goals. In this work, we describe our approach to building such a model for the US Marine Corps, and demonstrate the model's use by solving a particular equipment allocation problem. We combine object-oriented simulation with new concepts for workload modelling and measuring effectiveness that are based on the operational tasks the Marines perform.