1. A scheduling method for a multiprocessor for scheduling the order of assignment of execution units processed in parallel and subject to scheduling to a plurality of processors, comprising: sequentially retrieving at least one group, each including at least one execution unit subject to scheduling, from a ready queue, the ready queue storing groups in a ready state; referring to a schedule table which holds execution units in relation to processors to which the execution units are assigned; setting up flags for the processors to which the execution units are assigned, when the execution units belonging to a group retrieved from the ready queue are listed in the schedule table; appending the retrieved group to an assignment list storing groups that are candidates for assignment to respective processors, when the execution units belonging to the retrieved group are not listed in the schedule table and when all execution units belonging to the retrieved group are assignable to the respective processors at the same time; and assigning all execution units belonging to the groups stored in the assignment list to the respective processors for which flags are not set up in the schedule table.