A schedule arbitration server is configured to obtain a first scheduling constraint and first schedule information from a first server, and obtain a second scheduling constraint and second schedule information from a second server; detect a discrepancy between the first schedule information and the second schedule information, based on the first scheduling constraint, the first schedule information, the second scheduling constraint, and the second schedule information, and on overall optimization constraint information; recreate a schedule when a discrepancy is detected, by creating third and fourth schedule information through modification of the first schedule information and the second schedule information; calculate a first credit for the first server and a second credit for the second server, based on degrees of modification; and send the third schedule information and the first credit to the first server, and send the fourth schedule information and the second credit to the second server.