Nurse scheduling with tabu search and strategic oscillation

The problem of producing rosters for nursing staff in a large general hospital is tackled using tabu search with strategic oscillation. The objective is to ensure that enough nurses are on duty at all times while taking account of individual preferences and requests for days off in a way that is seen to treat all employees fairly. This is achieved using a variant of tabu search which repeatedly oscillates between finding a feasible cover, and improving it in terms of preference costs. Within each phase the search is controlled by a combination of different neighbourhoods and candidate lists designed to aggressively seek out local optima and then to react to the problems encountered on arrival. The result is a robust and effective method which is able to match the quality of solutions produced by a human expert.