PURPOSE: To improve the performance of a multiprocessor system by measuring the idle time of an unused processor by generating a task schedule via the processor in case the measured idle time exceeds a fixed level.

CONSTITUTION: When a task schedule is produced at a time point T1 by a processor 1 of a multiprocessor system, a 1st processor selection means 50 selects a processor and confirms the processors 2-N except the processor 1 to retrieve the unused processors. In case processors 1 and 3 are unused, a processor allocating means 70 updates an idle counter of a task schedule control table 30 and schedules for the processor allocation waiting tasks against the unused processors selected by the means 50. Then the idle counters are set at the initial values to both processors 1 and 3, and the task queues of the table 30 are allocated to the processors 1 and 3.