# Vehicle Routing Problem with several constraints.

I need to consider the vehicle routing problem(VRP) with following constraints:

1) The number of vehicle is $N$.

2) The number of deport is $M$.

3) Different vehicles have different capacities.

4) There are line-haul and back-haul customers, services for them can be mixed.

Can anyone give me some suggestion on such subject?

-
You should explain a bit what the VRP is, or provide a link to definitions. –  Benoît Kloeckner May 10 '13 at 11:58