1. A multiprocessor system which repeatedly executes task sets, each including a plurality of tasks, the multiprocessor system comprising: a plurality of processors, each including a task scheduler that determines a task execution order of the tasks in a task set to be executed by the processors within a task period which is defined as a period in repeated execution of the task sets, and processors that to execute the respective tasks; and a scheduler management device having a command unit configured to issue a command for at least one of the task schedulers to change the task execution order, wherein each of the task schedulers, when receiving the command from the command unit, changes the task execution order of the processors.