Simulation Networking (SIMNET) provides a means to supplement collective field training, but research is needed to develop a SIMNET training strategy. The U.S. Army Research Institute (ARI) and Perceptronics developed a prototype PC-based Unit Performance Assessment System (UPAS) to collect time-tagged data on firing events and vehicle status from the SIMNET network and display data summaries. The UPAS is intended to assist in preparing unit performance summaries necessary to provide units with feedback during After Action Reviews (AARs) and conduct training research. This paper describes a project by ARI and the Institute for Simulation and Training (IST) involving the design and software implementation of procedures for combining network data with non-network data within the UPAS to support the preparation of improved AAR aids. These aids may be applied to future generations of networked simulators such as the Close Combat Tactical Trainer (CCTT).