An efficient translation scheme for representing nurse rostering problems as satisfiability problems

In this paper we present efficient translation schemes for converting nurse rostering problem instances into satisfiability problems (SAT). We define eight generic constraints types allowing the representation of a large number of nurse rostering constraints commonly found in literature. For each of the generic constraint types, we present efficient translation schemes to SAT. Special attention is paid to the representation of counting constraints. We developed a two way translation scheme for counting constraints using O(nlogn) variables and O(n2) clauses. We translated the instances of the First international nurse rostering competition 2010 to SAT and proved the infeasibility of the instances. The SAT translation was used for a hardness study of nurse rostering problem instances based on SAT features.status: publishe