An Improved GRASP Interactive Approach for the Vehicle Routing Problem with Backhauls

The aim of the interactivity is to integrate the insight and experience of the user, and the power and precision of the heuristics in an interactive environment. An interactive approach enables us to search for a solution by means of a trial and error procedure, in which man and machine divide the tasks in accordance with their best respective capabilities. The machine is by far superior in what concerns calculations and exhaustive search tasks. The human user is superior in judging fuzzy situations. Through interaction the user is able to control the solution process by selecting initial parameters, selecting algorithms and adjusting solutions. Furthermore, special knowledge of the real life problem can be included. In this way the user guides the heuristics towards promising parts of the solution space.