A power assignment system and method determine a needed amount of power for propelling a vehicle system along a route and identify propulsion-generating vehicles for inclusion in the vehicle system based on power capabilities of the one or more propulsion-generating vehicles. Handling parameters of the vehicle system are determined for different groups of the propulsion-generating vehicles, and the propulsion-generating vehicles in at least one of the groups are selected based on the handling parameters. The selected propulsion-generating vehicles are included in the vehicle system during actual travel of the vehicle system along the route during the trip.