This generation device: acquires an operation plan for an electric vehicle; generates candidates of a charge and discharge plan for each of a plurality of batteries; excludes, from the candidates of a charge and discharge plan on the basis of the operation plan, a candidate of a charge and discharge plan including charging and discharging in an unconnected period to a power supply system of the electric vehicle, and a candidate of a charge and discharge plan in which the residual amount of a consumed battery of the electric vehicle cannot be secured, which is scheduled in the unconnected period; calculates the operation costs of the power supply system for the respective candidates of the charge and discharge plan except for the excluded candidates; determines a charge and discharge plan on the basis of the operation costs; and outputs the determined charge and discharge plan.