On the idle time control for multistep scheduling algorithm in parallel and distributed processing

This paper considers a task scheduling problem in heterogeneous systems of processors and proposes a multistep scheduling algorithm for the problem. There are two important points for task scheduling problem. First, it is necessarily to consider optimality. Second, it is necessarily to reduce scheduling time which is calculation time for the problem. For first point, idle time and communication costs among processors are very important factors. Idle time is time which a processor does not work. Then, this paper proposes a multistep scheduling algorithm considered idle time and communication costs.