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

A new VRPPD model and a hybrid heuristic solution approach for e-tailing

We analyze a business model for e-supermarkets to enable multi-product sourcing capacity through co-opetition (collaborative competition). The logistics aspect of our approach is to design and execute a network system where “premium” goods are acquired from vendors at multiple locations in the supply network and delivered to customers. Our specific goals are to: (i) investigate the role of premium product offerings in creating critical mass and profit; (ii) develop a model for the multiple-pickup single-delivery vehicle routing problem in the presence of multiple vendors; and (iii) propose a hybrid solution approach. To solve the problem introduced in this paper, we develop a hybrid metaheuristic approach that uses a Genetic Algorithm for vendor selection and allocation, and a modified savings algorithm for the capacitated VRP with multiple pickup, single delivery and time windows (CVRPMPDTW). The proposed Genetic Algorithm guides the search for optimal vendor pickup location decisions, and for each generated solution in the genetic population, a corresponding CVRPMPDTW is solved using the savings algorithm. We validate our solution approach against published VRPTW solutions and also test our algorithm with Solomon instances modified for CVRPMPDTW

Individually Rational Collaborative Vehicle Routing through Give-And-Take Exchanges

In this paper, we are concerned with the automated exchange of orders between logistics companies in a marketplace platform to optimize total revenues. We introduce a novel multi-agent approach to this problem, focusing on the Collaborative Vehicle Routing Problem (CVRP) through the lens of individual rationality. Our proposed algorithm applies the principles of Vehicle Routing Problem (VRP) to pairs of vehicles from different logistics companies, optimizing the overall routes while considering standard VRP constraints plus individual rationality constraints. By facilitating cooperation among competing logistics agents through a Give-and-Take approach, we show that it is possible to reduce travel distance and increase operational efficiency system-wide. More importantly, our approach ensures individual rationality and faster convergence, which are important properties of ensuring the long-term sustainability of the marketplace platform. We demonstrate the efficacy of our approach through extensive experiments using real-world test data from major logistics companies. The results reveal our algorithm's ability to rapidly identify numerous optimal solutions, underscoring its practical applicability and potential to transform the logistics industry.Comment: 7 pages 4 figures This paper was presented in the IJCAI 2023 First International Workshop on Search and Planning with Complex Objectives (WoSePCO) http://idm-lab.org/wiki/complex-objectiv

Vehicle Routing under Consideration of Transhipment in Horizontal Coalitions of Freight Carriers

AbstractIn order to reduce operational costs related to transportation activities in road haulage, small and medium-sized freight carriers can establish horizontal coalitions and share their resources. Through exchange of customer requests with other members within the coalition, carriers can improve the operational efficiency of their transportation processes. In this paper, transhipment is integrated into the conventional pickup and delivery problem in the collaborative context. Specifically, vehicles involved in transferring the same request are synchronized at the transhipment points. A mixed-integer programming model is proposed for this problem. Based on this model the benefits of transhipment are analysed. Computational results show considerable cost-savings enabled by transhipment in the operational planning of carrier coalitions

Optimization of customer orders routing in a collaborative distribution network

This paper presents a sequential approach for the assessment of a multi-layered distribution network from a cluster of collaborating suppliers to a large set of customers. The transportation network includes three segments: suppliers routes from suppliers to a consolidation and distribution center, full truckload routes toward regional distribution centers, and less-than-truckload distribution toward final customers. In every shipping date, the optimization problem consists of assigning customers to regional distribution centers and determining the routes of vehicles through the whole distribution network. This problem is first modeled as a Mixed Integer Linear Problem (MILP). Then, we propose to decompose it into three smaller MILPs that are solved sequentially in order to quickly provide a good approximate solution. The experiments on real data show that the decomposition method provides near optimal solutions within a few minutes while the original model would require hours of calculation

algorithms for a vehicle routing tool supporting express freight delivery in small trucking companies

Abstract We present a tool to support the operations manager of small trucking companies. The tool integrates modules to manage pickup/delivery requests, determine initial assignment to trucks and service routes, react to dynamic events, support demand forecasting. Modules are interconnected by a cloud platform and take advantage from real-time data sharing. The core of the tool is a neighborhood search heuristic for a Vehicle Routing Problem with side attributes, to be solved in both static and dynamic settings. The efficiency of the algorithm is improved by enhanced search strategies, neighbor filtering and parallel implementation. A prototype implementation of the tool currently supports the operations at Trans-cel, a small freight transportation company. Tests on the field on different operational scenarios show that the algorithm fits both static and dynamic settings in terms of running times and quality of the suggested solutions

Operative Planning with Exchangeable and Mandatory Tasks : Applications to Lot Size Planning and Transportation Planning

Lot-sizing problems of manufacturers and transportation planning problems of forwarders are presented and analyzed in this thesis. These problems represent crucial planning tasks in supply chain management. Due to high fluctuations and competitive markets, companies within supply chains use internal and external resources for the fulfillment of tasks. The thesis claims to contribute to the following topics: (1) introducing mandatory tasks for the DULR, IOTPP, CTPP, and CIOTPP as well as (2) presenting computational studies that demonstrate how much the costs of companies increase due to mandatory tasks. Mandatory tasks are tasks, which have to be fulfilled by appointed resources due to contractual obligations. A lack of research is identified in terms of this topic. It is usually assumed that a task can be fulfilled by any internal or external resources. The thesis describes how these planning tasks with mandatory tasks can be solved by using operations research. Therefore, existing mathematical models and solution approaches have to be extended. The thesis focuses on the determination of the impact of mandatory tasks based on computational studies