A communicator communicates with a plurality of management targets. An operation-mode determiner determines, based on information representing a status of each of the management targets each received by the communicator, whether a total system status of the plurality of management targets satisfies a predefined condition. A mode-of-network-communication switch, a communication-parameter changer, a condition-for-device-communication setter, a cycle-for-obtaining-status-value setter and a communication-parameter setter adjust, when the operation-mode determiner determines that the system status satisfies the predefined condition, a communication status of the communicator in accordance with the system status and a processing performance of the device.