The problem of delivery by multiple vehicles is known as the Vehicle Routing Problem (VRP). In a VRP, the goal is to build a set of routes, so that each visit is performed exactly once. The aim is to minimize the global cost of these routes. The side constraints of a VRP, such as time windows or capacity constraints, make it necessary to create several routes. A solution to a VRP assigns customers to routes and builds those routes.

The following figure shows a sample solution for a VRP:

The first step is to write a natural language description of the problem.

The components of the routing model for this VRP include: vehicles, customers, and a depot.

What are the constraints in this problem?

The objective is to minimize the cost of the delivery of all the goods.