Timetable merging for the Periodic Event Scheduling Problem

We propose a new mixed integer programming based heuristic for computing benchmark primal solutions instances of the PESPlib. The PESPlib is collection Periodic Event Scheduling Problem (PESP), comprising periodic timetabling problems inspired by real-world railway settings, and attracting several international research teams during last years. describe two strategies to merge set good timetables. These make use instance structure minimum weight cycle bases, finally leading restricted formulations with tighter variable bounds. Implementing this timetable merging approach in concurrent solver, we improve objective values best known smallest largest 1.7 4.3 percent, respectively.