1. A method of performing a real-time operation including a combination of a plurality of tasks, the method comprising: inputting structural description information and a plurality of programs describing procedures corresponding to the tasks, the structural description information indicating a relationship in input/output between the programs and including cost information concerning a time required for executing each of the programs; determining an execution start timing and execution term of each of a plurality of threads for execution of the programs based on the structural description information; and performing a scheduling operation of assigning the threads to one or more processors according to a result of the determining.