ROUTING AND SCHEDULING WITH TIME WINDOWS SOLVED BY NETWORK RELAXATION AND BRANCH-AND-BOUND ON TIME VARIABLES. FROM THE BOOK COMPUTER SCHEDULING OF PUBLIC TRANSPORT 2

Consider a set of trips where each trip is specified a priori by a place of origin, a destination, a duration, a cost and a time interval within which the trip must begin. The trips may include visits to one or more specific points. Our problem is to determine the number of vehicles required together with their routes and schedules, so that each trip begins within its given interval, while the fixed costs related to the number of vehicles, and the travel costs between trips are minimized. The problem is a generalization of the m-traveling salesman problem.