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1

Application of metaheuristics for multi-trip capacitated vehicle routing problem with time window

Niyomphon Kantapong, Nakkiew Warisa

Production Engineering Archives

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2024

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Vol. 30, Iss. 3

303--313

EN

This study focuses on the delivery routing problem faced by a transport company located in Phuket, Thailand. The goal of this study is to find a daily optimum route in order to minimize the total trans portation cost, which comprises fixed costs associated with vehicle rental and variable costs calculated based on factors of travel distance, fuel prices, and fuel consumption. The complexity of this problem is compounded by the fact that customer demand often exceeds a vehicle capacity, in terms of weight and volume. In addition, delivery must be made within specific time windows. To tackle this issue, the delivery routing problem is classified as a multi-trip capacitated vehicle routing problem with time window (MTCVRPTW). Since the problem is NP-hard, an application of metaheuristic is more prac tical to determine the delivery routing of the company within a reasonable computing time. In this study, Particle Swarm Optimization (PSO) and Differential Evolution (DE) algorithm are applied to solve MTCVRPTW. The numerical results show that DE provides better solution quality compared to those obtained from PSO and company current practices.

2

Enhancing vaccine distribution efficiency in Sri Lanka's cold chain through unmanned aerial systems: a district-based approach

Gunaratne Kalani, Weerasinghe Buddhi, Nielsen Izabela, Bocewicz Grzegorz, Thibbotuwawa Amila, Banaszak Zbigniew

LogForum

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2024

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Vol. 20, no. 1

97--116

EN

Background: With their high speed and low response time, unmanned aerial vehicles (UAVs) have been suggested as a solution to overcome the systematic inefficiencies in the current vaccine cold chain of Sri Lanka. The implementation of unmanned aerial systems (UASs) at the district level is recommended to maintain the end-to-end effectiveness of the program. Under the suggested distribution network, vaccines are transported directly from the Regional Medical Supplies Division (RMSD) warehouse to the respective health facilities, bypassing the Medical Officer of Health (MOH) unit warehouse. However, the use of UAVs is not appropriate in every RMSD due to the high fixed cost of a UAS. Methods: To determine an appropriate division, a suitability analysis was conducted by intersecting eight factors with their weights of importance. Suitable factors were determined using previous literature and weights of importance were calculated by an expert survey. Results: From the analysis, it was determined that the Kurunegala division is the most appropriate for UAV implementation. Therefore, Kurunegala is recommended as a starting point for the implementation of the proposed UAV-inclusive delivery system in Sri Lanka to realize its potential benefits and practical implications. Furthermore, it was found that a uniform solution involving only UAVs offers greater advantages compared to a mixed solution involving both trucks and UAVs. Nonetheless, owing to limited technological expertise and resistance to change in low-income nations, it is advisable to begin with a mixed approach and gradually transition to a uniform strategy in the coming years. Conclusions: The newly developed random search algorithm for the cyclic delivery synchronization problem gives results that are close to those obtained with mixed-integer programming. The main advantage of the algorithm is the reduction in computing time, which is relevant to the utilization of this method in practice, especially for larger problems.

3

Optimizing petroleum redistribution in Sri Lanka: A cost-benefit transportation model

Jayarathna Nuwan

Journal of Sustainable Development of Transport and Logistics

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2024

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Vol. 9, No. 1

121--136

EN

This case study is based on Ceylon Petroleum Corporation, Sri Lanka, the national oil and gas company and market leader in Sri Lanka. The company’s outbound logistics consists of a centralized distribution method and a redistribution process of its products across the island. However, this study mainly focused on one regional depot and one petroleum product, Kotagala depot and Lanka Auto Diesel. The currently centralized redistribution process has noticed extra routing costs due to the unreasonable consumption of additional distance. This problem is modelled as a variant of the vehicle routing problem with a heterogeneous vehicle fleet. Our objective is to minimize the routing costs (or milk-run) by imposing constraints on the capacity and the volume. The researcher introduces a centralized vehicle routing problem that is presented. The proposed vehicle routing problem has been used to find the optimal path between clusters. The computational investigation highlights the cost savings that this new VRP can accrue. Cost savings can be accrued as large as 32.35% compared to a company's existing method.

4

Optymalizacja tras pojazdów z wykorzystaniem algorytmów kwantowych

Rudnicka Zofia, Pręgowska Agnieszka

IPPT Reports on Fundamental Technological Research

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2024

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nr 2

97--128

PL

Problem marszrutyzacji (optymalizacji trasy) jest kwintesencją problemu optymalizacji kombinatorycznej w badaniach operacyjnych, który ma głębokie implikacje dla logistyki, zarządzania łańcuchem dostaw i systemów transportowych. Jego celem jest określenie najbardziej efektywnych tras dla floty pojazdów do obsługi grupy klientów, biorąc pod uwagę różnego rodzaju ograniczenie, takie jak pojemność pojazdu, okna czasu dostawy i długość trasy. Skuteczne rozwiązanie problemów marszruty ma kluczowe znaczenie dla minimalizacji kosztów operacyjnych, skrócenia czasu dostaw i łagodzenia wpływu na środowisko. Jednakże złożoność tego typu obliczeń rośnie wykładniczo wraz z liczbą klientów i pojazdów, co sprawia, że znalezienie optymalnych rozwiązań w rozsądnych ramach czasowych dla klasycznych algorytmów staje się wyzwaniem obliczeniowym. Z drugiej strony, obliczenia kwantowe, oferują nowatorski paradygmat rozwiązywania złożonych problemów optymalizacyjnych, takich jak problem marszrutyzacji. W artykule zbadano zastosowanie algorytmów kwantowych do optymalizacji tras pojazdów, koncentrując się na ich potencjale w zakresie przezwyciężania ograniczeń klasycznych metod w obsłudze eksplozji kombinatorycznej charakterystycznej dla problemów marszrutyzacji. Zaproponowano podejście hybrydowe, łączące algorytm przybliżonej optymalizacji kwantowej z algorytmem optymalizacji za pomocą roju cząstek. Analizowano zagadnienie związane z wyznaczeniem optymalnych tras pojazdów, które miały obsłużyć 250 klientów. W implementacji kwantowego algorytmu optymalizacyjnego wykorzystano łącznie 251 kubitów. Uzyskane wyniki pokazują, że przy wykorzystaniu metod hybrydowych można skutecznie planować trasy pojazdów.

EN

The vehicle routing problem (VRP) is a quintessential combinatorial optimization problem in operations research that has profound implications for logistics, supply chain management, and transportation systems. Its goal is to determine the most efficient routes for a fleet of vehicles to serve a group of customers, considering various constraints such as vehicle capacity, delivery time windows, and route length. Effectively solving VRP is crucial to minimizing operational costs, reducing delivery times, and mitigating environmental impacts. However, the complexity of this type of computation increases exponentially with the number of customers and vehicles, which makes finding optimal solutions within a reasonable time frame for classical algorithms a computational challenge. On the other hand, quantum computing (QC) offers a novel paradigm for solving complex optimization problems, such as the routing problem. In this paper, the QC application for vehicle route optimization, with a special emphasis on their potential to overcome the limitations of classical methods in handling the combinatorial explosion VRP characteristic has been studied. A hybrid approach was proposed combining an approximate quantum optimization algorithm with a particle swarm optimization algorithm. The problem of determining optimal vehicle routes to serve 250 customers was analyzed. A total of 251 qubits were used to implement the quantum optimization algorithm. The results obtained show that vehicle routes can be effectively planned using hybrid methods.

5

Optimizing Unmanned Aerial Vehicle for food delivery through vehicle routing problem: a comparative analysis of three delivery systems

Edirimanne Rumesh, Fernando W. Madushan Fernando, Nielsen Peter, Perera H. Niles, Thibbotuwawa Amila

Applied Computer Science

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2024

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Vol. 20, no. 1

85--105

EN

In recent times, there has been a notable increase in interest surrounding the integration of Un-manned Aerial Vehicle (UAV) technology and vehicle routing problems (VRP) for package delivery purposes. While existing studies have explored various types of package deliveries utilizing VRP, limited attention has been given to on-demand food delivery. This study aims to develop a VRP model that incorporates practical constraints such as payload capacity and maximum flying range, with the primary objective of minimizing travel distance in food delivery operations. A comparative analysis is conducted among three delivery methods, including UAV delivery, to determine the most effective approach and assess the feasibility of each method. Through a case study analysis focused on a pizza delivery service in Sri Lanka, it was observed that implementing VRP in a motorbike delivery system resulted in reduced travel distance, time, cost, and CO2 emissions compared to the existing delivery system. Furthermore, the utilization of UAVs in conjunction with VRP yielded even greater improvements across all parameters. Based on a comprehensive cost analysis considering long-term operations, the UAV-based delivery system was identified as the most cost-effective method, followed by the VRP-incorporated motorbike delivery method. Although the VRP-incorporated motorbike delivery system exhibited a slightly higher average time per route compared to the existing method, the total travel time required to complete all routes remained lower. Consequently, the study concludes that the VRP-incorporated motorbike delivery system outperforms the existing delivery method for food delivery, with the use of UAVs incorporating VRP identified as the optimal delivery method among the three alternatives. The findings contribute valuable insights to the optimization of food delivery logistics, emphasizing the potential of VRP and exploring the feasibility of UAVs for sustainable and efficient long-term delivery solutions.

6

Wybrane zagadnienia kształtowania systemu dystrybucji ładunków z wykorzystaniem rowerów towarowych wewnątrz aglomeracji miejskiej

Starczewski Jakub

Transport Miejski i Regionalny

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2023

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nr 1

3--8

PL

Artykuł podejmuje problematykę poprawy efektywności dostaw ładunków w zabytkowych centrach dużych miast i aglomeracji przy wykorzystaniu rowerów towarowych. Stanowi on opis wybranych zagadnień wchodzących w zakres rozprawy doktorskiej autora [1]. W artykule zaprezentowano model matematyczny systemu dostaw, w ramach którego zidentyfikowane zostały następujące elementy: kryterium oceny efektywności systemu, model popytu na dostawę ładunków, metody trasowania pojazdów oraz metody wyboru lokalizacji punktów przeładunkowych. Wszystkie elementy zostały scharakteryzowane w późniejszych częściach tekstu. Zaproponowano podejście do ewaluacji systemów dostaw ładunków poprzez identyfikację wskaźnika oceny efektywności uwzględniającego wymiar ekonomiczny procesu technologicznego oraz założenia strategii zrównoważonego rozwoju. Sformalizowano sposób obliczenia poszczególnych składowych wskaźnika oceny efektywności. Część badawcza obejmuje charakteryzację dwóch eksperymentów symulacyjnych przeprowadzonych za pomocą specjalnie stworzonego oprogramowania. Pierwszy z nich zrealizowano przy wykorzystaniu zaproponowanej metody analizy statystycznej wskaźnika oceny efektywności oraz heurystycznej metody środka ciężkości. Dotyczył on wyznaczenia lokalizacji punktu przeładunkowego na potrzeby rowerowego systemu dystrybucji. Drugi natomiast polegał na ocenie trzech metod marszrutyzacji (algorytmu oszczędzania Clarke’a–Wrighta, symulowanego wyżarzania i algorytmu genetycznego) w kontekście wartości przyjętego wskaźnika oceny efektywności. Jego przebieg odbywał się zgodnie z opracowanym planem eksperymentu pełno-czynnikowego, uwzględniającego zmienność popytu na przewozy ładunków. Całość zakończono wnioskami płynącymi z zaprezentowanej pracy badawczej, a także zaproponowano dalsze kierunki badań i rozwoju tematyki.

EN

The article deals with the issue of improving the efficiency of cargo delivery in agglomerations, using cargo bikes. It is a description of selected issues falling within the scope of the dissertation with the same title. The article presents a mathematical model of the delivery system, including elements that have been identified: the criterion for evaluating the system’s effectiveness, the model of demand for the cargo delivery, the methods of vehicle routing and the methods of choosing the reloading points’ location. An approach to the evaluation of cargo delivery systems w as proposed by identifying an efficiency assessment indicator, which takes into account the economic dimension of the technological process and the assumptions of the sustainable development strategy. The research includes the characteristics of two simulation experiments. First was conducted using the proposed method of statistical analysis of the effectiveness evaluation indicator and the heuristic method – the center of gravity method. Second was consisted in evaluating three vehicle routing methods. The article was summed up with conclusions from the presented research. Moreover, further directions of research and development of the subject were proposed.

7

Vehicle routing problem simultaneous deliveries and pickups with split loads and time windows with genetic algorithm (case study in shipping company)

Ferdianti Shea Amanda, Widyadana I Gede Agus

LogForum

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2023

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Vol. 19, no. 4

577--593

EN

Background: This research addresses a Vehicle Routing Problem with Simultaneous Delivery and Pickup, Split Loads, and Time Windows (VRPSDPSLTW). In this research, the VRPSDPSLTW problem is adapted for Company X, a shipping company based in Surabaya. The main goal is to enhance the optimal utilization of vessel capacity in the field of shipping transportation and logistics. Little previous research has been done on VRPSDPSLTW at a shipping company. Methods: The optimization approach employed was the Genetic Algorithm (GA), which serves as a metaheuristic to effectively optimize vessel capacity utilization. The algorithm uses One Point Crossover and Swap Mutation operators and analyzes various mutation parameters to determine the best configuration. The GA was coded in R, and experiments were conducted to obtain the best parameter for the GA. Results: The research yielded several outcomes, including route plans, loaded and unloaded Twenty-Foot Equivalent Units (TEUs), travel times, and trip utility from the point of loading (POL) to the point of delivery (POD). In total, there were 85 port visits, surpassing the initial count of 35 ports. Some ports were visited multiple times, with the exception of Surabaya, which served as the home base for a fleet of 15 vessels. The average trip duration was approximately 35 days. Through experimentation, it was determined that employing 1,000 generations along with a mutation probability of 0.2 produces improved solutions. The Genetic Algorithm solution enhanced the average vessel capacity utilization, increasing it to 80.93%. This represents a significant 21.23% increase compared to the global average of 59.7% observed for similar vessel usage scenarios. Conclusions: Furthermore, through the introduction of novel route opportunities, the contributions of each vessel were effectively enhanced. This achievement resulted in an optimal average vessel capacity utilization that met the demand. The findings strongly advocate for the employment of the Genetic Algorithm, highlighting its potential to substantially improve vessel capacity utilization. Consequently, this approach has played a pivotal role in elevating the efficiency of transportation and logistics operations for Company X.

8

Identifying the potential of unmanned aerial vehicle routing for emergency blood distribution

Dewmini Janani, Fernando W. Madushan, Nielsen Izabela Iwa, Bocewicz Grzegorz, Thibbotuwawa Amila, Banaszak Zbigniew

Applied Computer Science

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2023

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Vol. 19, no. 4

68--87

EN

This study is focusing on identifying the potential of Unmanned Aerial Vehicle (UAV) routing for blood distribution in emergency requests in Sri Lanka compared to existing transportation modes. Capacitated Unmanned Aerial Vehicle Routing Problem was used as the methodology to find the optimal distribution plan between blood banks directing emergency requests. The developed UAV routing model was tested for different instances to compare the results. Finally, the proposed distribution process via UAVs was compared with the current distribution process for the objective function set up in the model and other Key Performance Indicators (KPIs) including energy consumption savings and operational cost savings. The average percentage reduction in distribution time, reduction in energy consumption costs and reduction in operating costs per day using UAVs was 58.57%, 96.35% and 61.20% respectively for the instances tested using the model, highlighting the potential of UAVs. Therefore, the deficiencies in Sri Lanka's present blood delivery system can be addressed using UAVs' potential for time, cost, and energy savings. The ability to save time through the deployment of UAVs to the fleet during emergency situations plays a crucial role in preventing the loss of human lives.

9

Model doboru pojazdów do zadań w transporcie drogowym z wykorzystaniem aplikacji log-hub i solver

Jóźwiak Arkadiusz, Malczewska Ewa, Jachimowski Roland

Systemy Logistyczne Wojsk

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2021

|

Vol. 55, no. 2

193--212

PL

Na podstawie dostępnej literatury, charakterystyki zadań transportowych realizowanych w sieciach transportowych i podziale środków transportowych ze względu na realizowane zadania został opracowany model doboru pojazdów do zadań w transporcie drogowym z wykorzystaniem aplikacji log-hub i solver bazując na arkuszu kalkulacyjnym Excel. Model składa się z kilku elementów: arkusza do obliczania odległości i czasu przejazdu na podstawie kodów pocztowych lub nazw miejscowości, bazy dostępnych pojazdów, które mogą mieć 10 różnych ładowności, 3 sieci dla których można dobrać pojazdy ze względu na minimalizacje kosztów oraz arkusza wspomagającego podejmowanie decyzji dotyczących doboru pojazdów do zadań. Model uwzględnia różnice w czasie jazdy różnymi pojazdami na tej samej trasie (czas jazdy dla samochodu osobowego i ciągnika siodłowego) oraz różny czas rozładunku dla pojazdów o różnej ładowności. Przedmiotem analizy jest przewóz paletowych jednostek ładunkowych, niewymagających zapewnienia specjalnych warunków przejazdu. Model opiera się na pojazdach o nadwoziu uniwersalnym. Analizie podlegały 3 sieci. Z analizy wynika, że sieć 1 jest czysto teoretyczną siecią z perspektywy przewoźnika i transportu ładunków. Koszty w niej są o połowę niższe niż w przypadku sieci 2. Sieć 3 służy do dobrania pojazdów dla kilku lokalizacji, przy założeniu, że wszystkie wyruszają z tej samej miejscowości. Na podstawie opracowanego i zweryfikowanego modelu wywnioskowano, iż podczas analizy kosztów powinno się brać pod uwagę realny, a nie abstrakcyjny układ sieci (zazwyczaj pojazdy muszą dojechać do miejsca załadunku i po wykonaniu zadania dojechać z miejsca rozładunku do innego punktu, co generuje koszty i wpływa na wydłużenie czasu przejazdu). Należy unikać zadań, które odbywają się na krótkich odcinkach i wymagają długich dojazdów (generuje to największe koszty). Pojazdy o mniejszej ładowności szybciej realizują zadania, dlatego sprawdzą się bardziej do transportu ładunków, które wymagają minimalizacji czasu przejazdu lub dużej dynamiki dostaw.

EN

Based on the available literature, the characteristics of transport tasks carried out in transport networks and the division of means of transport due to the tasks performed, a model of vehicle selection for road transport tasks was developed using the log-hub and solver applications based on the Excel spreadsheet. The model consists of several elements: a sheet for calculating the distance and travel time based on postal codes or city names, a database of available vehicles that may have 10 different load capacities, 3 networks for which vehicles can be selected due to cost minimization, and a sheet supporting the taking decisions regarding the selection of vehicles for the tasks. The model takes into account the differences in driving times for different vehicles on the same route (driving time for a passenger car and a tractor unit) and different unloading times for vehicles with different load capacities. The subject of the analysis is the transport of pallet loading units that do not require special transport conditions. The model is based on vehicles with a universal body. 3 networks were analyzed. The analysis shows that network 1 is a purely theoretical network from the perspective of the carrier and freight transport. It costs half that of network 2. Network 3 is used to select vehicles for several locations, assuming that they all depart from the same town. On the basis of the developed and verified model, it was concluded that during the cost analysis one should take into account the real, not abstract network layout (usually vehicles must reach the place of loading and after completing the task, go from the place of unloading to another point, which generates costs and travel time extension). You should avoid tasks that take place over short distances and require long journeys (this is the most costly). Vehicles with a lower load capacity perform tasks faster, therefore they are more suitable for the transport of loads that require minimization of travel time or high dynamics of deliveries.

10

A logistic optimization for the vehicle routing problem through a case study in the food industry

Akpinar Muhammet Enes

LogForum

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2021

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Vol. 17, no. 3

387--397

EN

Background: In this study, the food delivery problem faced by a food company is discussed. There are seven different regions where the company serves food and a certain number of customers in each region. The time of requesting food for each customer varies according to the shift situation. This type of problem is referred to as a vehicle routing problem with time windows in the literature and the main aim of the study is to minimize the total travel distance of the vehicles. The second aim is to determine which vehicle will follow which route in the region by using the least amount of vehicle according to the desired mealtime. Methods: In this study, genetic algorithm methodology is used for the solution of the problem. Metaheuristic algorithms are used for problems that contain multiple combinations and cannot be solved in a reasonable time. Thus in this study, a solution to this problem in a reasonable time is obtained by using the genetic algorithm method. The advantage of this method is to find the most appropriate solution by trying possible solutions with a certain number of populations. Results: Different population sizes are considered in the study. 1000 iterations are made for each population. According to the genetic algorithm results, the best result is obtained in the lowest population size. The total distance has been shortened by about 14% with this method. Besides, the number of vehicles in each region and which vehicle will serve to whom has also been determined. This study, which is a real-life application, has provided serious profitability to the food company even from this region alone. Besides, there have been improvements at different rates in each of the seven regions. Customers' ability to receive service at any time has maximized customer satisfaction and increased the ability to work in the long term. Conclusions: The method and results used in the study were positive for the food company. However, the metaheuristic algorithm used in this study does not guarantee an optimal result. Therefore, mathematical models or simulation models can be considered in terms of future studies. Besides, in addition to the time windows problem, the pickup problem can also be taken into account and different solution proposals can be developed.

11

Modeling a cost benefit transportation model to optimize the redistribution process: Evidence study from Sri Lanka

Jayarathna D. G. Nuwan Dhammika, Lanel G. H. J., Juman Z. A. M. S.

Journal of Sustainable Development of Transport and Logistics

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2021

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Vol. 6, No. 2

43--59

EN

This study is a case study based on Softlogic Retail (Pvt) Ltd, Sri Lanka, which is a famous consumer electronics company and market leader in Sri Lanka. This company’s outbound logistics have been considered in this research, and they are mainly forced into the redistribution process in Sri Lanka. Extra routing costs due to unreasonable consumption of additional distance have been noticed in the current redistribution process. Here, this problem is modeled as a variant of the vehicle routing problem with a heterogeneous vehicle fleet. Our objective is to minimize warehouse operation, administration, and transportation costs by imposing constraints on capacity and volume. The researchers propose new heuristic solutions to the problem. A proposed heuristic algorithm has been used to find the optimal path between clusters. The computational investigation highlights the cost savings that can be accrued by this new heuristic. The cost savings can be accrued at a rate of as much as 37.5 % compared to the company’s existing method.

12

Optimal vehicle route schedules in picking up and delivering cargo containers considering time windows in logistics distribution networks: A case study

Le Thi Diem Chau, Nguyen Duy Duc, Oláh Judit, Pakurár Miklós

Production Engineering Archives

|

2020

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Vol. 26, Iss. 4

174--184

EN

This study describes a pickup and delivery vehicle routing problem, considering time windows in reality. The problem of tractor truck routes is formulated by a mixed integer programming model. Besides this, three algorithms - a guided local search, a tabu search, and simulated annealing - are proposed as solutions. The aims of our study are to optimize the number of internal tractor trucks used, and create optimal routes in order to minimize total logistics costs, including the fixed and variable costs of an internal vehicle group and the renting cost of external vehicles. Besides, our study also evaluates both the quality of solutions and the time to find optimal solutions to select the best suitable algorithm for the real problem mentioned above. A novel mathematical model is formulated by OR tools for Python. Compared to the current solution, our results reduced total costs by 18%, increased the proportion of orders completed by internal vehicles (84%), and the proportion of orders delivered on time (100%). Our study provides a mathematical model with time constraints and large job volumes for a complex distribution network in reality. The proposed mathematical model provides effective solutions for making decisions at logistics companies. Furthermore, our study emphasizes that simulated annealing is a more suitable algorithm than the two others for this vehicle routing problem.

13

Draft model of delivery routes at a city logistics scale when applying the Clarke-Wright method

Stopka Ondrej

Archiwum Motoryzacji

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2020

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Vol. 87, nr 1

67--80

EN

The manuscript deals with the subject of determining the optimal delivery routes in terms of supplying urban distribution centers when minimizing the distance traveled in a particular region for the purpose of addressing city logistics issues using the specific Operations Research method, namely the Clarke-Wright method. Thus, the main paper objective is to examine the issue: what are the optimal transport journeys from the specific object among individual customers in a certain region in order to execute minimum transport performance? First two sections of the manuscript specify the relevant concepts regarding the issue of distribution tasks and vehicle routing problem, and presents data and methods in relation to this research study. The most significant part of the article models the individual routes to determine the optimal interconnections of urban distribution center and their supply from one logistics service center in a regional logistics network at a city logistics scale when applying the Clarke-Wright method. The last sections of the elaborated research study evaluate the major findings and discuss the possible future initiatives in the topic addressed.

14

Improving unloading time prediction for vehicle routing problem based on GPS data

Žunić Emir, Kuric Amar, Delalić Sead

Annals of Computer Science and Information Systems

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2020

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Vol. 22

45--49

EN

The problem of transport optimization is of great importance for the successful operation of distribution companies. To successfully find routes, it is necessary to provide accurate input data on orders, customer location, vehicle fleet, depots, and delivery restrictions. Most of the input data can be provided through the order creation process or the use of various online services. One of the most important inputs is an estimate of the unloading time of the goods for each customer. The number of customers that the vehicle serves during the day directly depends on the time of unloading. This estimate depends on the number of items, weight and volume of orders, but also on the specifics of customers, such as the proximity of parking or crowds at the unloading location. Customers repeat over time, and unloading time can be calculated from GPS data history. The paper describes the innovative application of machine learning techniques and delivery history obtained through a GPS vehicle tracking system for a more accurate estimate of unloading time. The application of techniques gave quality results and significantly improved the accuracy of unloading time data by 83.27% compared to previously used methods. The proposed method has been implemented for some of the largest distribution companies in Bosnia and Herzegovina.

15

Cluster-based approach for successful solving real-world vehicle routing problems

Žunić Emir, Đonko Dženana, Šupić Haris, Delalić Sead

Annals of Computer Science and Information Systems

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2020

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Vol. 21

619--626

EN

Vehicle routing problem as the generalization of the Travelling Salesman Problem (TSP) is one of the most studied optimization problems. Industry itself pays special attention to this problem, since transportation is one of the most crucial segments in supplying goods. This paper presents an innovative cluster-based approach for the successful solving of real-world vehicle routing problems that can involve extremely complex VRP problems with many customers needing to be served. The validation of the entire approach was based on the real data of a distribution company, with transport savings being in a range of 10-20 %. At the same time, the transportation routes are completely feasible, satisfying all the realistic constraints and conditions.

16

The Impact of perturbation mechanisms on the operation of the swap heuristic

Misztal Wojciech

Archiwum Motoryzacji

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2019

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Vol. 86, nr 4

27--39

EN

In this study, an attempt was made to assess the impact of the most popular perturbation movements (i.e. Multiple-Swap(2-2), Multiple-Shift(2-2) and Multiple-K-Shift(1)), as well as the number of their calls on the quality of solutions and the time in which Swap(2-1) heuristics returns them. For this purpose, the iterative local search algorithm (ILS) was triggered, in which Swap(2-1) heuristics has cooperated with a single perturbation mechanism. The number of perturbations was changed in the range from 1 to 30. Each time the time and the difference between the percentage improvement of the objective function value of the solution obtained utilizing the Swap(2-1) algorithm cooperating with the perturbation mechanism and this algorithm working alone was checked. Based on the results obtained, it was found that the overall level of improvement in the quality of the returned solution is similar when using all of the considered perturbation mechanisms (is in the range of 2.49% to 4.02%). It has been observed that increasing the number of initiated perturbations does not guarantee an improvement in the quality of the returned solution. Perturbation movements similar to the motion initiated by the local search algorithm do not significantly improve the solution (they only entail extending the duration of action). The structure of the study has the following form. The Introduction chapter provides information on the Vehicle Routing Problem. The chapter Research methods contain a description of ILS and Swap(2-1) approaches and perturbation mechanisms considered. The last two chapters include the results of tests and conclusions.

17

Innovative modular approach based on vehicle routing problem and ant colony optimization for order splitting in real warehouses

Žunić Emir, Delalić Sead, Tucaković Zlatan, Hodžić Kerim, Beširević Admir

Annals of Computer Science and Information Systems

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2019

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Vol. 20

125--129

EN

A crucial part to any warehouse workflow is the process of order picking. Orders can significantly vary in the number of items, mass, volume and the total path needed to collect all the items. Some orders can be picked by just one worker, while others are required to be split up and shrunk down, so that they can be assigned to multiple workers. This paper describes the complete process of optimal order splitting. The process consists of evaluating if a given order requires to be split, determining the number of orders it needs to be split into, assigning items for every worker and optimizing the order picking routes. The complete order splitting process can be used both with and without the logistic data (mass and volume), but having logistic data improves the accuracy. Final step of the algorithm is reduction to Vehicle Routing Problem where the total number of vehicles is known beforehand. The process described in this paper is implemented in some of the largest warehouses in Bosnia and Herzegovina.

18

Marszrutyzacja pojazdów dystrybucyjnych: metoda optymalizacji i ocena wpływu zastosowanego sposobu wyznaczania ścieżek w sieci transportowej

Szczepański Emilian

Systemy Logistyczne Wojsk

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2018

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Vol. 48, no. 1

300--312

PL

Celem artykułu jest prezentacja metody wyznaczania tras pojazdów dystrybucyjnych i ocena wpływu zastosowanego sposobu wyznaczania ścieżek między węzłami w sieci transportowej.Realizacja celu wymagała sformułowania modelu matematycznego odwzorowującego system dystrybucji ładunków i zadania optymalizacyjnego.Przedstawiono metodę optymalizacyjną opartą o algorytmy genetyczne i modyfikację algorytmu A-star do wyznaczania ścieżek.W artykule porównano wyznaczanie marszrut dla pojazdów dystrybucyjnych z punktu widzenia zastosowanego podejścia do wyznaczania ścieżek.

EN

The aim of the article is to present themethodfordetermining routes of distribution vehicles and to assess the impact of the method used to determine the pathbetween nodes in the transport network. The implementation of the goal required the formulation of a mathematical model of the cargo distribution system and the optimization task. An optimization method based on genetic algorithms as well as modification of A-star forpathfindingwere presented. The articles compare the vehicle routing problem solution from the point of view of the approach used to determine paths.

19

Decision support system in freight transport based on vehicle routing problem with quality criterion

Szczepański E., Jachimowski R., Żak J.

Archives of Transport System Telematics

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2018

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Vol. 11, iss. 3

49--56

EN

Deliveries planning in transport systems is a complicated task and require taking into account a wide range of factors. Enterprises wanting to propose solutions that meet the clients’ needs and be competitive on the market must prepare their offer based on decision support systems including factors characteristic for the real process. The aim of the article is to present a concept of a decision support system based on a multi-criteria vehicle routing problem in real conditions (Real-World VRP). Taking into account the latest trends in the optimization of the delivery plan, the model includes three criteria - the cost, time and success rate of the delivery plan as a criterion relating to the quality of the delivery plan. Among other assumptions, it should be pointed out that the heterogeneous structure of the rolling stock has been taken into account, the number of which is not limited, the vehicles return to the place of origin. The travel time of the connection and the time of loading operations are random variables. The limited driver’s work time and driving time were also applied. The effect of the work presented in the article is the concept of the decision support system in the freight transport, taking into account the quality criterion of the delivery plan.

20

Effective Solutions to the Transport Distribution of Material by the Mayer Method

Čejka Jiří, Stopka Ondrej

Advances in Science and Technology. Research Journal

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2018

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Vol. 12, no 4.

177--183

EN

This paper deals with streamlining the collection (pick-up) and distribution (delivery) activities within the technology of wood industry. Through the optimization process implemented using the issue of the distribution task of linear programming, specifically the Mayer method, the particular solution in order to minimize the total costs in practice of utilized distribution routes is proposed. The first part of the paper presents the characteristics of the vehicle routing problem and describes methods of solving this issue. Subsequently, the main part of the paper outlines a particular case study in the context of the Mayer method application within the field of transport-technology solution of the material distribution.