Parallel solutions for preemptive makespan scheduling on two identical machines

Research output: Contribution to journalArticlepeer-review


We consider online preemptive scheduling of jobs arriving one by one, to be assigned to two identical machines, with the goal of makespan minimization. We study the effect of selecting the best solution out of two independent solutions constructed in parallel in an online fashion. Two cases are analyzed, where one case is purely online, and in the other one jobs are presented sorted by non-increasing sizes. We show that using two solutions rather than one improves the performance significantly, but that an optimal solution cannot be obtained for any constant number of solutions constructed in parallel. Our algorithms have the best possible competitive ratios out of algorithms for each one of the classes.

Original languageEnglish
Pages (from-to)61-76
Number of pages16
JournalJournal of Scheduling
Issue number1
StatePublished - Feb 2023

Bibliographical note

Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.


  • Competitive ratio
  • Jobs arriving over a list
  • Parallel solutions
  • Preemptive scheduling

ASJC Scopus subject areas

  • Software
  • General Engineering
  • Management Science and Operations Research
  • Artificial Intelligence


Dive into the research topics of 'Parallel solutions for preemptive makespan scheduling on two identical machines'. Together they form a unique fingerprint.

Cite this