Capstone Projects

Wisconsin Library Delivery Services & the Vehicle Routing Problem: A Case Study of Proposals from the Public Library System Redesign Project

Program: Data Science Master's
Location: Wisconsin (onsite)
Student: Timothy Drexler

In 2015, the Wisconsin Department of Public Instruction launched the Public Library System Redesign project to create a plan for reconfiguring Wisconsin’s public library systems and the provision of system services, including the statewide interlibrary loan delivery service. As part of that project, a Delivery Workgroup developed two proposals for shifting to a service model based on regional delivery service territories where local libraries would receive delivery stops on routes originating from a regional hub. For this project, I investigated the feasibility of these proposals by modeling regional library delivery services using a variant of the Vehicle Routing Problem and the Google OR-Tools package available for the Python programming language. Given a set of constraints and input data representing real-world distances and travel times retrieved from Google Maps, the OR-Tools routing solver determined whether a feasible route structure existed in the region and suggested a route configuration to minimize total route time. By varying the input parameters for the regional VRPs, I explored how different constraint values and solution search strategies affected routing solver outcomes. The results indicate that the number of routes necessary to serve every library and the volume capacity of the vehicles in the regional fleet will significantly influence the ability of route planners to design a workable route structure.