Competitive On-Line Scheduling with Level of Service

AbstractMotivated by an application in thinwire visualization, we study an abstract on-line scheduling problem where the size of each requested service can be scaled down by the scheduler. Thus, our problem embodies a notion of “Level of Service” that is increasingly important in multimedia applications. We give two schedulers $$FirstFit$$ and $$EndFit$$ based on two simple heuristics, and generalize them into a class of greedy schedulers. We show that both $$FirstFit$$ and $$EndFit$$ are 2-competitive, and any greedy scheduler is 3-competitive. These bounds are shown to be tight.