Constraints and search efficiency in nurse scheduling problem

The nurse scheduling problem (NSP) is that of allocating shifts for nurses under various constraints. Generally, the extensive number of constraints requires a great knowledge and experience to make a nurse´s scheduling table. This task requires a lot of time and effort and there is demand for an automatic scheduling. This study focuses the relationship between constraints and search efficiency, and discusses the affect for search efficiency, with the way to take the constraints into GA. This paper especially focuses the constraints that must be satisfied absolutely in the coding and genetic operations, and shows that his method can reduce the search area of GA drastically using numerical approximation method. Scheduling tables are acquired by the conventional and proposed method, and the result shows that effective search can be done and effective nurse scheduling tables can be generated by the proposed method.