The Product Director Light Tactical Vehicles (PdD LTV) is responsible for the Army’s High Mobility Multipurpose Wheeled Vehicle (HMMWV) family of vehicles. Due to the large number of variants found throughout the Army plus the continued need for their service into the foreseeable future, the Army has conducted extensive depot recapitalization programs and continues to explore modernization options to sustain enduring requirements. Because competing performance requirements exist and budget constraints demand careful design choices, PdD LTV commissioned the development of a Whole System Trades Analysis Tool (WSTAT) specified for the HMMWV family of vehicles to help gain an analytic understanding of the key performance, cost, risk, and growth tradeoffs inherent within their potential designs. The WSTAT provides a holistic framework for modeling and understanding these tradeoffs. In this paper, the overarching WSTAT methodology is presented along with the specific implementation for HMMWV. Several example results are then provided to demonstrate the types of decision support enabled by the WSTAT capability.