Hybrid MIP-CP Techniques to Solve a Multi-Machine Assignment and Scheduling Problem in Xpress-CP

  • Alkis Vazacopoulos
  • Nitin Verma
Part of the Applied Optimization book series (APOP, volume 98)


In this paper we introduce Xpress-CP—a Constraint Programming tool-and demonstrate its modeling and solving capabilities. We consider the multi-machine assignment and scheduling problem (Hooker et al. (1999)), where jobs, with release dates and deadlines, have to be processed on parallel unrelated machines (where processing times depend on machine assignment). Given a job/machine assignment cost matrix, the objective is to minimize the total cost while keeping all machine schedules feasible. We show that by deriving the benefits of MIP and CP techniques simultaneously this problem can be modeled and solved efficiently in a hybrid fashion using Xpress Optimization suite.


Schedule Problem Assignment Problem Constraint Programming Master Problem Total Processing Time 
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Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • Alkis Vazacopoulos
    • 1
  • Nitin Verma
    • 1
  1. 1.Dash Optimization, IncEnglewood CliffsUSA

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