High operational availability that allows tactical ground vehicles to execute operational tasks to satisfy mission capability requirements is crucial to combat brigade effectiveness. Hence, we have developed a simulation model to understand the impact of mission demands and tactical ground vehicle reliability on operational availability. This model was built for the DOT&E sponsored Ground Combat Vehicle Analysis Tools Study conducted at the Institute for Defense Analyses during summer of 2011. The model to be presented assesses the operational availability of a HBCT fleet of ground vehicles by representing (1) Mobil repair teams, (2) Recovery vehicles, (3) Collection point repair services, and (4) Parts deliveries as a queuing network simulation. The inputs for this model may include vehicle reliability data, repair times, failure modes, part availability, vehicle recovery times, and maintenance staffing. However many of the inputs are optional, so the model can flexibly accommodate incomplete data sets. During this talk, the audience will gain insight on how mission demands and vehicle reliability affect operational availability. In addition, we will also explore to what extent can any availability issues be mitigated by additional repair resources and improved part delivery logistics.