Vehicle Routing Problem in Pharmaceuticals Distribution and Genetic Algorithm Application

Abstract

Since vehicle routing problem was first expressed in mathematical terms in late 1950s, it has found ways of application for many daily problems in different disciplines (waste collection, product transportation from warehouses to supermarkets, school buses etc.) as well as being one of the most academically researched subjects. Apart from small scale problems, vehicle routing problem becomes np-hard combinatorial optimization problem especially when trying to solve real daily life problems. Therefore, although heuristic algorithms do not guarantee optimum results, they are used quite often in vehicle routing problems.In this study, the routing problem of a main pharmaceuticals warehouse for delivering orders to 200 pharmacies operating in three different cities and their districts is solved using genetic algorithm, one of the most effective and most used heuristic algorithms. The model devised in the study determines distribution route from the main warehouse to pharmacies with minimum cost by minimizing total travel distance and number of vehicles and using vehicle capacities in the most effective way possible. In the end, two optimum solutions with regards to various aspects such as total distance and number of vehicles are presented with their cost values.