Scheduling Independent Tasks with Due Times on a Uniform Processor System

An algori thm to preemptively schedule n tasks on m uniform processors is presented. It is assumed that each task is available at t ime 0. Associated with each task is a due time by which it is to be completed. The algorithm schedules all tasks to complete by their due times whenever possible. The asymptotic time complexity of the algorithm is O(n log n + ran). It generates O(mn) preemptions in the worst case. An example of n tasks requiring O(mn) preemptions is also presented. The algorithm can also be used when all tasks have the same due times but different release times.