When a user logs in and inputs document data into a box, a usage history of the box as used by the user is determined by referring to a user information management table. If there is a record, process attributes are set, and a process associated with the box is executed. If there is no record, a message indicating that there is no record is displayed. If execution is selected in response to this display, the process is executed. Once the process has ended, the usage record of the box as used by the user is updated to "used".