A tactical multi-week implicit tour scheduling model with applications in healthcare

In many healthcare tactical scheduling analyses, we need to solve large tour scheduling problems in which required staffing levels vary by time of day and day of week. A tour is a set of shift start times and shift lengths worked over a scheduling horizon of one or more weeks. As the degree of scheduling flexibility increases, the resulting tour scheduling problems get larger and this increase in size is exacerbated when the scheduling horizon is longer than one week. In this article, we present a tactical multi-week implicit tour scheduling model intended to complement operational scheduling systems. The implicit nature of the model allows us to solve problems that would be prohibitively large if modeled using traditional explicit tour scheduling approaches. We incorporate a variety of tour types with both intra-tour start time and shift length flexibility as well as varying degrees of weekend flexibility. We test the performance of our models on a set of medical units with different demand patterns. Computational experiments have shown that the developed implicit model can play an important role in quantifying trade-offs between labor costs, understaffing levels and scheduling flexibility. Our models have been released as an open source project in the hopes of facilitating practitioner use and also providing access to other scheduling researchers.