VRP algorithms for decision support systems to evaluate collaborative urban freight transport systems

This paper proposes a comparison between genetic and semi-greedy algorithms for a collaborative VRP in city logistics. In order to compare the performance of both algorithms on real-size test cases, we develop a cluster-first route second algorithm. The clustering phase is made by a seep algorithm, which defines the number of used vehicles and assigns a set of customers to it. Then, for each vehicle, we build a min-cost route by two methods. The first is a semi-greedy algorithm. The second is a genetic algorithm. We test both approaches on real-size instances Computational results are presented and discussed.Cet article propose une comparaison entre algorithmes génétiques et semi-greedy pour un problème de tournées de véhicules collaboratif en logistique urbaine. Pour comparer les deux algorithmes, nous proposons des algorithmes séquentiels basés sur la même phase initiale, puis les tournées sont construites par des procédures différentes. La première est de type sem-greedy ; la deuxième un algorithme génétique. Des résultats sont presents et discutés

Two-echelon freight transport optimisation: unifying concepts via a systematic review

Multi-echelon distribution schemes are one of the most common strategies adopted by the transport companies in an aim of cost reduction, but their identification in scientific literature is not always easy due to a lack of unification. This paper presents the main concepts of two-echelon distribution via a systematic review, in the specific a meta-narrative analysis, in order to identify and unify the main concepts, issues and methods that can be helpful for scientists and transport practitioners. The problem of system cost optimisation in two-echelon freight transport systems is defined. Moreover, the main variants are synthetically presented and discussed. Finally, future research directions are proposed.location-routing problems, multi-echelon distribution, cross-docking, combinatorial optimisation, systematic review.

Freight distribution systems with cross-docking: a multidisciplinary analysis

Freight transport constitutes one of the main activities that influences economy and society, as it assures a vital link between suppliers and customers and it represents a major source of employment. Multi-echelon distribution is one of the most common strategies adopted by the transport companies in an aim of cost reduction. This paper presents the main concepts of multi-echelon distribution with cross-docks through a multidisciplinary analysis that includes an optimisation study (using both exact and heuristic methods), a geographic approach (based on the concept of accessibility) and a socio-economic analysis. a conceptual framework for logistics and transport pooling systems, as well as a simulation method for strategic planning optimisation.Freight transport systems, cross-docking, simulation, collaboration, socio-economic issues

Sustainable supply chain management in city logistics solutions: an experience's comeback from Cityporto Padua (Italy)

The sustainable logistics and transportation studies constitute a primordial research axis in the enterprises' governance. In the last years, many reflections and developments in logistics research have studied the economic and the environmental questions related to supply chain management, but only few of them consider sustainability in its totality. Moreover, in practice, city logistics systems conception and planning is currently following a sustainable approach. The aim of this paper is to start a reflection about the three dimensions of sustainable supply chain management (economic, environmental and social), and illustrate these concepts by the results of an experience's comeback from a city logistics system, Cityporto (Padua, Italy).Sustainable Supply Chain Management; experience's comeback; urban freight distribution

Sharing services for freight distribution: concepts, stakes and experience comebacks

La mutualisation logistique est un sujet très à la mode mais peu étudié dans la littérature scientifique. Ce document propose les concepts de base de la mutualisation logistique pour la distribution de marchandises, énonçant les principes de base et proposant deux modèles pour la conception et l'analyses de systèmes de distribution de marchandises avec une mutualisation de plusieurs opérations.Mutualisation logistique; supply chain management; aide aux décisions de groupe; logistique urbaine

Are City Logistics Solutions Sustainable? The Cityporto case

Urban logistics is a field that studies the best solutions for urban freight distribution with high environmental objectives. However, most actions are started by public authorities without taking into account the impacts of the new organizational schemas in the existing distribution enterprises' organization. This paper sets out to show that urban logistics approaches are currently important with reference to the noise and pollution in city center. To this end, we present the success experience of Cityporto (Padoua) in Italy. Cityporto is a service which makes deliveries in city centre by using GPL and electric lorries. So, the service is considered as less polluting as a conventional approach. In this context, it allows a delivery at any time of the day, also in the Limited Traffic Zone which is closed at certain hours of the day. This is based on the findings from an exploratory qualitative approach. Documentary analysis several interviews have be made. These concern three internal stakeholders of Interporto di Padova (the company which manages the intermodal platform of Padova, in charge of Cityporto) and one member of Padova's Municipality (which promote the project). The results of this case study show that environmental aspect is one of the foundations of the project, but the economic continuity has to be first ensured. Indeed, the preservation of this service on the long term is subjected to its solvency. Moreover, its success is associated to the recognition by employees, and also customers. With regard to the collected information, it is possible to propose a balanced scorecard, where three axes emerged in connexion with economic, environmental and social dimensions. The paper makes a contribution to the evaluation and measurement of city urban logistics using a success story that has been developed from the practitioner perspective. This experience could provide a basis for further practices in Italy and other European countries. In conclusion, the proposed case study is presented for its academic, policy and managerial implications. This experience conceptualises city logistics in relation with the Sustainable Development, setting the main objectives and steps of urban planning for freight distribution and logistics issues. But above all, it provides an understanding of the key success factors in a green transport organisation which can become a pivotal position in the upstream supply chain. De facto, the study should facilitate the implementation of green urban logistics taking into account the importance of the project's economic continuity.City logistics, sustainability, case study, qualitative research, management

Two-echelon freight transport optimisation: unifying concepts via a systematic review

Multi-echelon distribution schemes are one of the most common strategies adopted by the transport companies in an aim of cost reduction, but their identification in scientific literature is not always easy due to a lack of unification. This paper presents the main concepts of two-echelon distribution via a systematic review, in the specific a meta-narrative analysis, in order to identify and unify the main concepts, issues and methods that can be helpful for scientists and transport practitioners. The problem of system cost optimisation in two-echelon freight transport systems is defined. Moreover, the main variants are synthetically presented and discussed. Finally, future research directions are proposed

New trends on urban goods movement: Modelling and simulation of e-commerce distribution

In this paper, a modelling framework to complete the recent scientific works on urban goods modelling is proposed. More precisely, we introduce a substitution procedure that estimates the number of trips and the corresponding travelled distances for shopping drive, home delivery and reception points' strategies. Moreover, an appraisal of scenarios is proposed in order to study how these three new forms of proximity delivery services impact on the overall urban goods movement distribution. Starting from four extreme situations, we introduce more realistic scenarios in order to find a suitable combination of delivery strategies. All the scenarios are simulated using the proposed framework, and the main traffic issues related to e-commerce distribution channel are discussed. The best realistic combination promotes the joint usage of home deliveries and proximity reception points and allows a reduction of about 13% of the road occupancy rates in urban areas.urban goods movement, modelling, shopping trips, e-commerce

Simulation and optimization methods for logistics pooling in the outbound supply chain

Logistics pooling and collaborative transportation systems are relatively new concepts in logistics research, but are very popular in practice. This communication proposes a conceptual framework for logistics and transportation pooling systems, as well as a simulation method for strategic planning optimization. This method is based on a twostep constructive heuristic in order to estimate for big instances the transportation and storage costs at a macroscopic level. Four possible scenarios are explored and commented. Finally, a socio-economic analysis based on 20 semi-directive interviews is presented to propose the limitations and obstacles of logistics poolingLogistics pooling, supply chain management, optimization, group reasoning, simulation

End consumer goods movement generation in French medium urban areas

End-consumer movements, defined as the movements made by the consumer transporting the purchased goods, are identified with shopping trips. Whereas the logistics movements (freight distribution and urban part of the supply chain) are well studied in city logistics and urban planning, the end-consumer movements are usually related only to people movements. This paper presents a new modelling approach to characterise the shopping trips within a city logistics point of view, in order to connect these movements with those belonging to urban freight distribution in the supply chain. We present a trip generation model built from the data of recent household trip surveys, more precisely for the urban community of Lyon (France). We present the main results produced by the various simulations in a short-term planning horizon.Urban freight; trip generation modelling; simulation; urban policy; decision-making support