LECTURE #1 Roles of LPT List Scheduling on Parallel Machines
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چکیده
List Scheduling is an approach to finding an approximate non-preemptive schedule on parallel machines, initially due to Graham [4]. We present and analyze the approach for identical machines and an arbitrary jobs list. Then an algorithm based on the LPT (Longest Processing Time) list with an improved performance is discussed, based on [2, 5]. We stress the role of LPT schedules for determining the power of preemption, defined as the ratio of the makespan for the optimal non-preemptive schedule to the makespan of the optimal preemptive schedule. For identical parallel machines, we present the power of preemption results obtained in [1, 6, 7], while for uniform machines the results obtained in [8, 9, 10].
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