An apparatus predicts time-series variations in resource usage for logical structures for a future time period (a schedule period) on the basis of a history representing the history of resource usage by the logical structures. The apparatus attempts to select a plurality of arrangement candidates for which resource usage in each of a plurality of physical machines is equal to or less than a criterion for each of a plurality of time segments comprising the schedule period. The apparatus computes a migration cost of migrating the logical structures between physical machines for an arrangement according to a holistic arrangement plan for each of a plurality of holistic arrangement plans. Each of the plurality of holistic arrangement plans is a combination of a plurality of selected arrangement candidates corresponding to each of the plurality of time segments.