A Rich Vehicle Routing Problem for a City Logistics Problem

Daniela Ambrosino,Carmine Cerrone

doi:10.3390/math10020191

Abstract

In this work, a Rich Vehicle Routing Problem (RVRP) is faced for solving city logistic problems. In particular, we deal with the problem of a logistic company that has to define the best distribution strategy for obtaining an efficient usage of vehicles and for reducing transportation costs while serving customers with different priority demands during a given planning horizon. Thus, we deal with a multi-period vehicle routing problem with a heterogeneous fleet of vehicles, with customers’ requirements and company restrictions to satisfy, in which the fleet composition has to be daily defined. In fact, the company has a fleet of owned vehicles and the possibility to select, day by day, a certain number of vehicles from the fleet of a third-party company. Routing costs must be minimized together with the number of vehicles used. A mixed integer programming model is proposed, and an experimental campaign is presented for validating it. Tests have been used for evaluating the quality of the solutions in terms of both model behavior and service level to grant to the customers. Moreover, the benefits that can be obtained by postponing deliveries are evaluated. Results are discussed, and some conclusions are highlighted, including the possibility of formulating this problem in such a way as to use the general solver proposed in the recent literature. This seems to be the most interesting challenge to permit companies to improve the distribution activities.

Highlights

Distribution activities in urban areas represent a considerable part of the total cost of transport and are intended to grow for the emerging increment in the number of requests for pick up and deliveries [1]
Given a depot with a heterogeneous fleet of vehicles, a set of extra vehicles that can be required daily to a third part company, and a set of customers characterized by demand over a planning horizon for products with three different priorities, determine the best way to serve the customers in such a way to satisfy their demands by respecting required time windows, minimize the total kilometers traveled and the number of additional vehicles required to serve customers, while respecting law restrictions for drivers
We have analyzed a distribution strategy for reducing routing costs and the number of vehicles used for serving customers

Summary

Introduction

Distribution activities in urban areas represent a considerable part of the total cost of transport and are intended to grow for the emerging increment in the number of requests for pick up and deliveries [1]. Distribution companies may have either a heterogeneous fleet of vehicles or an undefined fleet (when they refer to third parties for having trucks); they must respect law restrictions for drivers and, may have policies to follow that can impose distribution conditions in respect to serving customers (i.e., related to the customer service level to grant, to the lead time to grant, and to the discounts that can be applied in case of delays) All these aspects generate new constraints that characterize the faced problem as an RVRP. The authors analyze a multi-depot network, where it is possible to use auxiliary depots for improving routing costs and permitting to anticipate deliveries; incompatibilities between customers and vehicles are considered This is different from our problem because we permit the postponement of a part of customers’.

Problem under Investigation

Method

First Analysis

Findings

Second Analysis

Conclusions