Crew size has become a critical issue in military vehicle design. Motivated by the needs of organizations such as the Army Materiel Systems Analysis Activity and the Future Combat System (FCS) lead system integrator, Boeing-Science Applications International Corporation, the U.S. Army Research Laboratory (ARL) decided to take the initiative to investigate this issue. The focus of this trade study was to determine the viability of transitioning to a two-soldier crew for the line-of-sight (LOS) and beyond-line-of-sight (BLOS) platforms in the early FCS force designs for Increment I. The LOS-BLOS platform is now called the mounted combat system (MCS). The two- versus three-soldier crew analysis was conducted with task-network models built with the computer simulation tool, Improved Performance Research Integration Tool (IMPRINT). IMPRINT was developed by ARL to evaluate possible system performance by calculating the mental workload associated with each operator to complete a specified mission. Within this trade study, these missions were simulated with networks of functions and tasks representative of possible missions that would be performed by FCS MCS crew members. This study focused on the LOS engagement portion of the MCS mission. The initial IMPRINT models were developed from existing IMPRINT models of other combat platforms. While the MCS platform should have greater capabilities than its predecessor, the functions of driving, shooting, and communicating are fundamentally the same. FCS concepts seek to equip the MCS crew with technology to enhance their mission performance. These initial models were to be the baseline concept, and the desire was to add technology to the models as applicable.