Scheduling patient appointments via multilevel template: a case study in chemotherapy

This paper studies a multi-criteria optimization problem which appears in the context of booking chemotherapy appointments. The main feature of the model under study is the requirement to book for each patient multiple appointments which should follow a pre-specified multi-day pattern. Each appointment involves several nurse activities which should also follow a pre-specified intra-day pattern. The main objectives are to minimize patients’ waiting times and peaks of nurses’ workload for an outpatient clinic. Our solution approach is based on the concept of a multi-level template schedule which is generated for a set of artificial patients with typical treatment patterns. There are two stages in template generation: the multi-day stage, which fixes appointment dates for all artificial patients, and the intra-day stage, which fixes for each day appointment starting times and patient allocation to nurses. The running schedule is created by considering actual patients one by one as they arrive to the clinic. Booking appointments for each new patient is performed by assigning appropriate dates and times of the template schedule following the prescribed multi-day and intra-day patterns. Additional rescheduling procedure is used to re-optimize intra-day schedules on a treatment day or shortly beforehand. The key stages of the scheduling process are modeled as integer linear programs and solved using CPLEX solver. We demonstrate the effectiveness of our approach through case-based scenarios derived from a real clinic and discuss the advantages that the multi-level template can bring.