The VRPTW is an important generalization of the VRP and a
basic distribution management problem that can be model
many real-world problems and which are consists of designing
a set of minimum cost routes, originating and terminating at a
central depot, for a fleet of vehicles which services a set of customers
with known demands. The customers must be assigned
exactly once to vehicles such that the vehicle capacities are not
exceeded. The service at a customer must begin within the time
window defined by earliest time and the latest time when the
customer permits the start of service. Some of the more useful
applications of the VRPTW include bank deliveries, postal
deliveries, industrial refuse collection, national franchise restaurant
deliveries, and school bus routing and security patrol
services.