The United States Army is embracing the use of new information technologies to achieve tactical advantage over potential adversaries. Existing and future informa tion systems place a significant load on the tactical data network, resulting in a bandwidth management crisis, yet there is no prioritization, allocation, planning, or manage ment tool available to simulate information flows over time for different communications configurations under different operational conditions. The development of such a tool requires the implementation of a communication network model and the supporting discrete-event simula tion system. Models for the information systems that induce flows, the command posts using the information systems, and the influence of operational conditions on the information flows are also required, as is a graphical user interface that allows the tactical planner to configure the system and set up data capture. The visual development techniques used in this tool make it easy for the planner to design and build communication networks to support operations, then interactively reconfigure the network, run “what-if” scenarios, and visualize the effects. The system can be used for training, design of experimental networks, and to support rapid decision-making. © 2001, Sage Publications. All rights reserved.