A task allocation time decision unit inputs a period of each of the tasks and a load factor of each of the tasks with respect to execution time of all tasks from a task context memory unit, and decides the task allocation time. A task occasion frequency computation unit computes a task occasion frequency. An execution time ratio computation unit computes an execution time ratio of each task with respect to a execution time of a certain task. A schedulability condition computation unit computes a conditional expression for enabling scheduling on the basis of the period. A task allocation time decision unit computes a task allocation time for enabling scheduling from the conditional expression and the execution time ratio and outputs the resultant task allocation time to a task allocation time display unit.