Multi-Product, Multi-Period Vehicle Routing Problem

Abstract

The Vehicle Routing Problem (VRP) is one of the most detailed problems in the Supply Chain area as it requires detailed information about the travel times and routing sequence. Many efforts were made to solve optimally the VRP under various configurations. However, due to the combinatorial nature of the problem, as it is proven to be NP-Hard problem, reaching optimal solution is not an easy task. Efforts are diverted to heuristic techniques and algorithms, looking for reaching near optimal solutions, besides that, they can easily be applied. Most of the developed heuristics and algorithms targeted the traditional VRP, in which, the distance travelled is minimized. Much less work was done to consider the role of integrating different decisions on determining such routes, such as the inventory and location decisions. In the present work, the traditional Inventory Location Routing Problem (ILRP) and the Inventory Location Routing Problem while applying the Vendor Managed Inventory (VMI) policy are considered. This is concerned with determining the depots to use, the dispatching times and routing of the vehicles and quantities to deliver to a given set of customers that need continuous constant demand rates of a number of products.