Dynamic appointment scheduling in priority queueing systems with access time targets

Multi-class priority queuing systems with access time targets and dynamic arrivals are common in many environments, including emergency, healthcare, logistics and hospitality services. This study focuses on the waiting line management of new cases in the specialist outpatient clinics of the Hospital Authority of Hong Kong. The objectives are to assign appointment dates in a way to fulfill the access time targets for urgent (highest priority) and semi-urgent (second highest priority) new cases while maintaining acceptable access time for non-urgent (routine) new cases. A dynamic appointment scheduling algorithm is developed and tested through simulated instances created from the waiting time data and hospital attendance data for a one-year horizon. The experimental results are compared with the reported performance statistics. Performances are also compared with results of the deterministic problem assuming the arrival data were given. For certain ordered set of objective weights relevant to the current problem, the deterministic problem can be formulated as a transportation model and solved optimally by the classical transportation algorithm with an additional checking procedure.