The Royal Derby Hospital is a large 1000 bed acute hospital with 40 operating theatres. It also accommodates a Graduate Entry Medical School run with the University of Nottingham. 4D-based RotaTrack tracks and assesses the viability of leave for all groups in order to arrive at a list of available staff. Controlling absences to maximise staff availability is essential to the hospital's operation. RotaTrack generates the rotas to ensure that an appropriately skilled clinician is present to lead and then allocates other clinicians according to their training requirements, balancing training against hospital service requirements. It also runs full on-call and shift rotas to provide 24/7 support and emergency services.