Branch-and-price approaches for the Multiperiod Technician Routing and Scheduling Problem

This paper addresses a technician routing and scheduling problem motivated by the case of an external maintenance provider. Technicians are proficient in different skills and paired into teams to perform maintenance tasks. Tasks are skill constrained and have time windows that may span multiple days. The objective is to determine the daily assignment of technicians into teams, of teams to tasks, and of teams to daily routes such that the operation costs are minimized. We propose a mixed integer program and a branch-and-price algorithm to solve this problem. Exploiting the structure of the problem, alternative formulations are used for the column generation-phase of the algorithm. Using real-world data from an external maintenance provider, we conduct numerical studies to evaluate the performance of our proposed solution approaches.