The SAINT model of the AN/TSQ-73 system demonstrates the ability to incorporate the human element into a digital simulation model of a complex command and control system. The model is extremely versatile and can be used to evaluate the effect of both human performance characteristics and system operating policies on overall system effectiveness for a wide range of mission scenarios. Continuing refinement and expansion of the model will enhance its ability to address complex issues associated with operator training as well as the design and operation of the AN/TSQ-73 system. In its present form the model can be used to systematically vary battlefield scenarios and study the resulting effects on operator error rates, response times, and task performance sequences. Potential use for an expanded version of the model include the identification of critical tasks based on simulated combat performance, resource or resupply bottlenecks, and optimal use of automatic or semiautomatic operational modes. A second year effort is presently under way to develop improved psychological models of target identification, track hooking operations, and fire unit message handling. (Author).