Non-combat tactical vehicle incidents such as rollover are one of the major causes of soldier injuries and deaths. Rollover incidents are usually associated with multiple impacts which result in complex interactions between occupants and hard structural components. Detailed information of occupant responses in such rollover incidents are lacking, and to design effective occupant protection system and safety restraints systems, understanding the vehicle to occupant interaction is essential. The performance of ground vehicles during a rollover event is an important safety and occupant protection requirement for military vehicles. Modeling and simulation are a very useful tool in study and investigation of vehicle rollover characteristics and countermeasure concepts. The main goal of this research is to develop an M&S model of a HMMWV full vehicle system and evaluate the effectiveness of the different restraints systems in a lateral 25 mph rollover tests and its effect on occupant response such as head, chest, pelvic accelerations and neck forces and moments. This M&S analysis will aim to correlate to the PM LTV and IMMI conducted lateral 25 mph rollover test with set of restraints systems and evaluate Analysis of Alternatives.