However it is easy to demonstrate just how difficult vehicle routing problems can be.

Several variations and specializations of the vehicle routing problem exist:

Vehicle routing problems.

MACS-VRPTW: a multiple ant colony system for vehicle routing problems with time windows.

In 2001, Concorde won a 5000 Guilder prize from CMG for solving a vehicle routing problem the company had posed in 1996.

The vehicle routing problem (VRP) is a combinatorial optimization and integer programming problem seeking to service a number of customers with a fleet of vehicles.

These include the vehicle routing problem (VRP) as well as the capacitated VRP, which require minor modification of the algorithm.

Vehicle Routing Problem with Time Windows (VRPTW): The delivery locations have time windows within which the deliveries (or visits) must be made.

Capacitated Vehicle Routing Problem (with or without Time Windows): CVRP or CVRPTW.

Vehicle Routing Problem with Pickup and Delivery (VRPPD): A number of goods need to be moved from certain pickup locations to other delivery locations.

SYMPHONY also has structure specific implementations for problems like the Traveling salesman problem, Vehicle routing problem, Set partitioning problem, Mixed postman problem etc.

To the casual observer the vehicle routing problem does not seem to present many difficulties - surely it is just a case of trying all combinations of visits and seeing which one is best (shortest/fastest/cheapest/etc)?

The method has been applied to several Combinatorial Optimization Problems including the Job-Shop Scheduling Problems , Flow-Shop Problems , Vehicle Routing Problems as well as many others.

Vehicle Routing Problem with LIFO: Similar to the VRPPD, except an additional restriction is placed on the loading of the vehicles: at any delivery location, the item being delivered must be the item most recently picked up.