4,496 research outputs found
The two-echelon capacitated vehicle routing problem: models and math-based heuristics
Multiechelon distribution systems are quite common in supply-chain and logistics. They are used by public administrations in their transportation and traffic planning strategies, as well as by companies, to model own distribution systems. In the literature, most of the studies address issues relating to the movement of flows throughout the system from their origins to their final destinations. Another recent trend is to focus on the management of the vehicle fleets required to provide transportation among different echelons. The aim of this paper is twofold. First, it introduces the family of two-echelon vehicle routing problems (VRPs), a term that broadly covers such settings, where the delivery from one or more depots to customers is managed by routing and consolidating freight through intermediate depots. Second, it considers in detail the basic version of two-echelon VRPs, the two-echelon capacitated VRP, which is an extension of the classical VRP in which the delivery is compulsorily delivered through intermediate depots, named satellites. A mathematical model for two-echelon capacitated VRP, some valid inequalities, and two math-heuristics based on the model are presented. Computational results of up to 50 customers and four satellites show the effectiveness of the methods developed
Factory Gate Pricing: An Analysis of the Dutch Retail Distribution
Factory Gate Pricing (FGP) is a relatively new phenomenon in retail distribution. Under FGP, products are no longer delivered at the retailer distribution center, but collected by the retailer at the factory gates of the suppliers. Owing to both the asymmetry in the distribution networks (the supplier sites greatly outnumber the retailer distribution centers) and the better inventory and transport coordination mechanisms, this is likely to result in high savings. A mathematical model was used to analyze the benefits of FGP for a case study in the Dutch retail sector. Extensive numerical results are presented to show the effect of the orchestration shift from supplier to retailer, the improved coordination mechanisms, and sector-wide cooperation.supply chain management;factory gate pricing;retail distribution
Factory Gate Pricing: An Analysis of the Dutch Retail Distribution
Factory Gate Pricing (FGP) is a relatively new phenomenon in retail distribution.Under FGP, products are no longer delivered at the retailer distribution center, but collected by the retailer at the factory gates of the suppliers.Owing to both the asymmetry in the distribution networks (the supplier sites greatly outnumber the retailer distribution centers) and the better inventory and transport coordination mechanisms, this is likely to result in high savings.A mathematical model was used to analyze the benefits of FGP for a case study in the Dutch retail sector.Extensive numerical results are presented to show the effect of the orchestration shift from supplier to retailer, the improved coordination mechanisms, and sector-wide cooperation.pricing;retailing;distribution;supply chain management;Netherlands
Optimization of a city logistics transportation system with mixed passengers and goods
International audienceIn this paper, we propose a mathematical model and an adaptive large neighborhood search to solve a two{tiered transportation problem arising in the distribution of goods in congested city cores. In the rst tier, goods are transported in city buses from a consolidation and distribution center to a set of bus stops. The main idea is to use the buses spare capacity to drive the goods in the city core. In the second tier, nal customers are distributed by a eet of near{zero emissions city freighters. This system requires transferring the goods from buses to city freighters at the bus stops. We model the corresponding optimization problem as a variant of the pickup and delivery problem with transfers and solve it with an adaptive large neighborhood search. To evaluate its results, lower bounds are calculated with a column generation approach. The algorithm is assessed on data sets derived from a eld study in the medium-sized city of La Rochelle in France
Network Migration Problem: A Logic-based Benders Decomposition Approach Driven by Column Generation and Constraint Programming
Telecommunication networks frequently face technological advancements and
need to upgrade their infrastructure. Adapting legacy networks to the latest
technology requires synchronized technicians responsible for migrating the
equipment. The goal of the network migration problem is to find an optimal plan
for this process. This is a defining step in the customer acquisition of
telecommunications service suppliers, and its outcome directly impacts the
network owners' purchasing behaviour. We propose the first exact method for the
network migration problem, a logic-based Benders decomposition approach that
benefits from a hybrid constraint programming-based column generation in its
master problem and a constraint programming model in its subproblem. This
integrated solution technique is applicable to any integer programming problem
with similar structure, most notably the vehicle routing problem with node
synchronization constraints. Comprehensive evaluation of our method over
instances based on six real networks demonstrates the computational efficiency
of the algorithm in obtaining quality solutions. We also show the merit of each
incorporated optimization paradigm in achieving this performance
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Resource constrained routing and scheduling: Review and research prospects
In the service industry, it is crucial to efficiently allocate scarce resources to perform tasks and meet particular service requirements. What considerably complicates matters is when these resources, for example skilled technicians, nurses, and home carers have to visit different customer locations. This paper provides a comprehensive survey on resource constrained routing and scheduling that unveils the problem characteristics with respect to resource qualifications, service requirements and problem objectives. It also identifies the most effective exact and heuristic algorithms for this class of problems. The paper closes with several research prospects
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