9 research outputs found
A study of vehicle routing problem via trade-off ranking method
Vehicle routing defines selecting the minimum cost, distance, and/or time path from a depot to several alternatives for a goods or service to reach its destination. The objective of most routing problem is to minimize the total cost of providing the service. But other objectives also may come into play, particularly in the public sector. For emergency services, such as ambulance, police, and fire engine, minimizing the response time to an incident is of primary importance. A few routing algorithms do not use a deterministic algorithm to find the "best" route for a goods to get from its original source to its destination. Instead, to avoid congestion, a few algorithms use a randomized algorithm that routes a path to a randomly picked intermediate destination, and from there to its true destination. In this paper, the trade-off ranking method is used to solve for the vehicle routing treated as a conflicting multi-criteria problem. The integration of the trade-off ranking method into the vehicle routing problem gives another perspective on how to solve the problem, hence broadened the decision support system for the vehicle routing problem
PENGOPTIMUMAN BIAYA DISTRIBUSI MENGGUNAKAN INTEGER PROGRAMMING DALAM MENYIKAPI KEBIJAKAN GANJIL-GENAP DI JAKARTA
Kebijakan Ganjil-Genap merupakan salah satu aturan yang diterapkan di Jakarta untuk mengurangi kemacetan. Kebijakan ini mengakibatkan kendaraan bermotor tidak bisa melalui ruas jalan tertentu, jika ganjil/genapnya nomor-polisi kendaraan tidak sesuai dengan ganjil/genapnya tanggal kendaraan tersebut ketika melintasi ruas jalan yang terkena kebijakan. Ada beberapa jenis kendaraan yang terkena dampak kebijakan ini, di antaranya ialah kendaraan distribusi perusahaan ekspedisi. Kebijakan ini membuat biaya distribusi perusahaan ekspedisi meningkat karena jarak perjalanan menuju konsumen menjadi lebih jauh untuk menghindari ruas jalan Ganjil-Genap ketika plat nomor polisi kendaraan yang digunakan untuk distribusi tidak sesuai dengan jenis tanggal distribusi. Proses distribusi yang meminimumkan biaya pengeluaran memerlukan penentuan rute yang optimal. Masalah penentuan rute optimal ini diformulasikan ke dalam Vehicle Routing Problem menggunakan Integer Linear Programming. Masalah ini diselesaikan menggunakan perangkat lunak LINGO 18.0 dan solusi optimal yang diperoleh berupa rute pendistribusian barang menggunakan kendaraan tertentu serta meminimumkan biaya distribusi
A novel Dynamic programming approach for Two-Echelon Capacitated Vehicle Routing Problem in City Logistics with Environmental considerations
Abstract The paper proposes a Two-Echelon Capacitated Vehicle Routing Problem with Environmental consideration, intended for managing urban freight distribution in City Logistics. It presents a novel Dynamic programming approach that divides the main problem into several ones and uses an exact algorithm to obtain optimal route paths. The approach applies Fuzzy C-Means Clustering for assigning a group of customers to a satellite. The initial solution is improved with roulette selection, 2-opt, and Or-opt exchange heuristics. The approach was tested on benchmark instances, and obtained results are satisfactory. Moreover, the proposed method highlights the environmental improvement we can obtain in managing urban freight transportation
A large neighbourhood based heuristic for two-echelon routing problems
In this paper, we address two optimisation problems arising in the context of
city logistics and two-level transportation systems. The two-echelon vehicle
routing problem and the two-echelon location routing problem seek to produce
vehicle itineraries to deliver goods to customers, with transits through
intermediate facilities. To efficiently solve these problems, we propose a
hybrid metaheuristic which combines enumerative local searches with
destroy-and-repair principles, as well as some tailored operators to optimise
the selections of intermediate facilities. We conduct extensive computational
experiments to investigate the contribution of these operators to the search
performance, and measure the performance of the method on both problem classes.
The proposed algorithm finds the current best known solutions, or better ones,
for 95% of the two-echelon vehicle routing problem benchmark instances.
Overall, for both problems, it achieves high-quality solutions within short
computing times. Finally, for future reference, we resolve inconsistencies
between different versions of benchmark instances, document their differences,
and provide them all online in a unified format
Two-Echelon Vehicle and UAV Routing for Post-Disaster Humanitarian Operations with Uncertain Demand
Humanitarian logistics service providers have two major responsibilities
immediately after a disaster: locating trapped people and routing aid to them.
These difficult operations are further hindered by failures in the
transportation and telecommunications networks, which are often rendered
unusable by the disaster at hand. In this work, we propose two-echelon vehicle
routing frameworks for performing these operations using aerial uncrewed
autonomous vehicles (UAVs or drones) to address the issues associated with
these failures. In our proposed frameworks, we assume that ground vehicles
cannot reach the trapped population directly, but they can only transport
drones from a depot to some intermediate locations. The drones launched from
these locations serve to both identify demands for medical and other aids
(e.g., epi-pens, medical supplies, dry food, water) and make deliveries to
satisfy them. Specifically, we present two decision frameworks, in which the
resulting optimization problem is formulated as a two-echelon vehicle routing
problem. The first framework addresses the problem in two stages: providing
telecommunications capabilities in the first stage and satisfying the resulting
demands in the second. To that end, two types of drones are considered. Hotspot
drones have the capability of providing cell phone and internet reception, and
hence are used to capture demands. Delivery drones are subsequently employed to
satisfy the observed demand. The second framework, on the other hand, addresses
the problem as a stochastic emergency aid delivery problem, which uses a
two-stage robust optimization model to handle demand uncertainty. To solve the
resulting models, we propose efficient and novel solution approaches
A branch-cut-and-price approach for the single-trip and multi-trip two-echelon vehicle routing problem with time windows
International audienceThe paper studies the two-echelon capacitated vehicle routing problem with time windows, in which delivery of freight from depots to customers is performed using intermediate facilities called satellites. We consider the variant of the problem with precedence constraints for unloading and loading freight at satellites. In this variant allows for storage and consolidation of freight at satellites. Thus, the total transportation cost may decrease in comparison with the alternative variant with exact freight synchronization at satellites. We suggest a mixed integer programming formulation for the problem with an exponential number of route variables and an exponential number of precedence constraints which link first-echelon and second-echelon routes. Routes at the second echelon connecting satellites and clients may consist of multiple trips and visit several satellites. A branch-cut-and-price algorithm is proposed to solve efficiently the problem. This is the first exact algorithm in the literature for the multi-trip variant of the problem. We also present a post-processing procedure to check whether the solution can be transformed to avoid freight consolidation and storage without increasing its transportation cost. It is shown that all single-trip literature instances solved to optimality admit optimal solutions of the same cost for both variants of the problem either with precedence constraints or with exact synchronization constraints. Experimental results reveal that our algorithm can be used to solve these instances significantly faster than another recent approach proposed in the literature
A branch-cut-and-price approach for the single-trip and multi-trip two-echelon vehicle routing problem with time windows
The paper studies the two-echelon capacitated vehicle routing problem with time windows, in which delivery of freight from depots to customers is performed using intermediate facilities called satellites. We consider the variant of the problem with precedence constraints for unloading and loading freight at satellites. This variant allows for storage and consolidation of freight at satellites. Thus, the total transportation cost may decrease in comparison with the alternative variant with exact freight synchronization at satellites. We suggest a mixed integer programming formulation for the problem with an exponential number of route variables and an exponential number of precedence constraints which link first-echelon and second-echelon routes. Routes at the second echelon connecting satellites and clients may consist of multiple trips and visit several satellites. A branch-cut-and-price algorithm is proposed to solve efficiently the problem. This is the first exact algorithm in the literature for the multi-trip variant of the problem. We also present a post-processing procedure to check whether the solution can be transformed to avoid freight consolidation and storage without increasing its transportation cost. Our algorithm significantly outperforms another recent one for the single-trip variant of the problem. We also show that all single-trip literature instances solved to optimality admit optimal solutions of the same cost for both variants of the problem either with precedence constraints or with exact synchronization constraints