The Marine Corps trains its commanders and their staffs under a number of constraints (time, money, training areas, etc.) New c3i systems and weapon systems require more training than ever before. One innovative tool the marine corps has developed is the tactical warfare simulation evaluation and analysis system (TWSEAS) it is, however, becoming obsolete and its replacement will require careful analysis of operational, functional, and system requirements and state-of-the art technology in order to provide the necessary interfaces with existing and planned c3i systems and to give the lowest possible life-cycle cost. This proposal addresses the conduct of a structured system analysis lending to the procuring of the replacement system.