VFMP-V benchmarks

[jcoupey]

Vehicle fleet mix problem (VFMP) are a class of HVRP (Heterogeneous VRP) problems that aim at deciding how to choose the fleet from an unlimited number of resources with different capacity and costs in order to assign all jobs. Cost differences across vehicles are usually described as 1. a different fixed cost for using a vehicle and 2. a multiplicative factor on top of the same cost matrix.

VFMP instances come in various flavors:

• VFMP-F have fixed costs only;
• VFMP-V have variable costs only;
• VFMP-FV have both.

Along with other HVRP instances, there are a few examples of those at https://perso.isima.fr/~lacomme/hvrp/hvrp.html.

Because we don't currently handle fixed costs, the only class we can easily work with is VFMP-V, which I've used during the work on VROOM-Project/vroom#450.

We should make available everything required to reproduce tests on the VFMP-V instances.

[jcoupey]

Above link also has HVRP instances with no fixed costs from Taillard (1999).