Assigning Sporadic Tasks to Unrelated Parallel Machines

  • Alberto Marchetti-Spaccamela
  • Cyriel Rutten
  • Suzanne van der Ster
  • Andreas Wiese
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7391)


We study the problem of assigning sporadic tasks to unrelated machines such that the tasks on each machine can be feasibly scheduled. Despite its importance for modern real-time systems, this problem has not been studied before. We present a polynomial-time algorithm which approximates the problem with a constant speedup factor of \(11+4\sqrt{3} \approx{17.9}\) and show that any polynomial-time algorithm needs a speedup factor of at least 2, unless P = NP. In the case of a constant number of machines we give a polynomial-time approximation scheme. Key to these results are two new relaxations of the demand bound function which yields a sufficient and necessary condition for a task system on a single machine to be feasible.


Task Assignment Speedup Factor Task System Earliest Deadline First Sporadic Task 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Alberto Marchetti-Spaccamela
    • 1
  • Cyriel Rutten
    • 2
  • Suzanne van der Ster
    • 3
  • Andreas Wiese
    • 1
  1. 1.Sapienza University of RomeRomeItaly
  2. 2.Maastricht UniversityMaastrichtThe Netherlands
  3. 3.Vrije UniversiteitAmsterdamThe Netherlands

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