A Constraint Integer Programming Approach for Resource-Constrained Project Scheduling

Abstract. We propose a hybrid approach for solving the resource-constrained project scheduling problem which is an extremely hard to solve combinatorial optimization problem of practical relevance. Jobs have to be scheduled on (renewable) resources subject to precedence constraints such that the resource capacities are never exceeded and the latest completion time of all jobs is minimized. The problem has challenged researchers from different communities, such as integer programming (IP), constraint programming (CP), and satisfiability testing (SAT). Still, there are instances with 60 jobs which have not been solved for many years. The currently best known approach, lazyFD, is a hybrid between CP and SAT techniques. In this paper we propose an even stronger hybridization by integrating all the three areas, IP, CP, and SAT, into a single branch-and-bound scheme. We show that lower bounds from the linear relaxation of the IP formulation and conflict analysis are key ingredients for pr...

• Type: Conference
• Year: 2010
• Where: CPAIOR
• Authors: Timo Berthold, Stefan Heinz, Marco E. Lübbecke, Rolf H. Möhring, Jens Schulz
• Keywords: Combinatorial Optimization Problem, CPAIOR 2010, Lower Bounds, Operations Research, Project Scheduling Problem