This paper aims to compare a two-echelon and a single-echelon distribution system. A mathematical model for the Single-Echelon Capacitated Vehicle Routing Problem (SE-CVRP) is proposed. This SE-CVRP is the counterpart of Two-Echelon Capacitated Vehicle Routing Problem (2E-CVRP) introduced in the authors’ previous work. The proposed mathematical model is Mixed-Integer Non-Linear Programming (MIN...

Multi-echelon distribution systems are quite common in supply-chain and logistic management. They are used by public administrations in their transportation and traffic planning strategies as well as by companies to model their distribution systems. In the literature, most studies address issues related to the movement of flows throughout the system from the origins to their final destinations....

Since the Vehicle Routing Problem (VRP) was introduced by Dantzig and Ramser, it became one of the most studied problems in Combinatorial Optimization. Different solution approaches were proposed over the past decades to solve the VRP and its variants. In this thesis, we discuss about two VRP variants, resulting from the integration of VRPs with distribution problems. The first problem takes pl...

Multi-echelon distribution systems are quite common in supply-chain and logistic management. They are used by public administrations in their transportation and traffic planning strategies as well as by companies to model their distribution systems. In the literature, most studies address issues related to the movement of flows throughout the system from the origins to their final destinations....

The efficient and timely distribution of freight goods is critical for supporting the demands of modern urban areas. Optimum freight ensures the survival and development of urban areas. In the contemporary logistic there are two main distribution strategies: direct distribution and multi-echelon distribution. In the direct distribution, means of transport, starting from the main distribution ce...

In Multi-Echelon Vehicle Routing Problems the delivery from one or more depots to the customers is managed by routing and consolidating the freight through intermediate depots, called satellites. This family of problems differs from Multi-Echelon Distribution Systems present in the literature. In the latter the attention is focused on the flow assignment among the levels only, while we also con...

We study the robust capacitated vehicle routing problem (CVRP) under demand uncertainty, which determines a minimum cost delivery of a product to geographically dispersed customers using capacity-constrained vehicles. Contrary to the deterministic CVRP, which postulates that the customer demands for the product are deterministic and known, the robust CVRP models the customer demands as random v...

Given the emergence of two-echelon distribution systems in several practical contexts, this paper tackles, at strategic level, a network design problem under uncertainty. This is defined as stochastic multi-period capacitated location-routing (2E-SM-CLRP). It considers partitioned into two echelons: each echelon involves specific location-assignment-transportation schema that must cope with fut...

In this paper, we present a branch-and-cut algorithm for the Vehicle Routing Problem with Two-dimensional Loading Constraints (2L-CVRP). The 2L-CVRP is a combination of the Capacitated Vehicle Routing Problem (CVRP) and the Two-dimensional Bin Packing Problem. We propose a strategy based on emphasizing cut generation using known families of valid inequalities for the CVRP. Checking packing feas...

The Vehicle Routing Problem (VRP) requires the determination of an optimal set of routes for a set of vehicles to serve a set of customers. We deal here with the Capacitated Vehicle Routing Problem (CVRP) where there is a maximum weight or volume that each vehicle can load. We developed an Ant Colony algorithm (ACO) for the CVRP based on the metaheuristic technique introduced by Colorni, Dorigo...