In an information processing system including a computer device and a storage device storing data used by the computer device, the region in which the data is held is managed in association with a change, over the passage of time, in the performance and availability required of the data holding region. The computer device includes a storage device managing unit for managing the storage device which stores data used by the computer device. The storage device managing unit periodically monitors temporal characteristics information, and moves data, if the storage region having functional characteristics corresponding to the temporal characteristics information is different from the storage region to which the data is currently assigned.