Efficient Edge-Finding on Unary Resources with Optional Activities

Revised and Extended Version
  • Sebastian Kuhnert
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5437)


Unary resources play a central role in modelling scheduling problems. Edge-finding is one of the most popular techniques to deal with unary resources in constraint programming environments. Often it depends on external factors if an activity will be included in the final schedule, making the activity optional. Currently known edge-finding algorithms cannot take optional activities into account. This paper introduces an edge-finding algorithm that finds restrictions for enabled and optional activities. The performance of this new algorithm is studied for modified job-shop and random-placement problems.


constraint-based scheduling global constraints optional tasks and activities unary resources 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Sebastian Kuhnert
    • 1
  1. 1.Institut für InformatikHumboldt-Universität zu BerlinBerlinGermany

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