228 research outputs found

    Arc routing problems: A review of the past, present, and future

    Full text link
    [EN] Arc routing problems (ARPs) are defined and introduced. Following a brief history of developments in this area of research, different types of ARPs are described that are currently relevant for study. In addition, particular features of ARPs that are important from a theoretical or practical point of view are discussed. A section on applications describes some of the changes that have occurred from early applications of ARP models to the present day and points the way to emerging topics for study. A final section provides information on libraries and instance repositories for ARPs. The review concludes with some perspectives on future research developments and opportunities for emerging applicationsThis research was supported by the Ministerio de Economia y Competitividad and Fondo Europeo de Desarrollo Regional, Grant/Award Number: PGC2018-099428-B-I00. The Research Council of Norway, Grant/Award Numbers: 246825/O70 (DynamITe), 263031/O70 (AXIOM).Corberån, Á.; Eglese, R.; Hasle, G.; Plana, I.; Sanchís Llopis, JM. (2021). Arc routing problems: A review of the past, present, and future. Networks. 77(1):88-115. https://doi.org/10.1002/net.21965S8811577

    An updated annotated bibliography on arc routing problems

    Get PDF
    The number of arc routing publications has increased significantly in the last decade. Such an increase justifies a second annotated bibliography, a sequel to Corberán and Prins (Networks 56 (2010), 50–69), discussing arc routing studies from 2010 onwards. These studies are grouped into three main sections: single vehicle problems, multiple vehicle problems and applications. Each main section catalogs problems according to their specifics. Section 2 is therefore composed of four subsections, namely: the Chinese Postman Problem, the Rural Postman Problem, the General Routing Problem (GRP) and Arc Routing Problems (ARPs) with profits. Section 3, devoted to the multiple vehicle case, begins with three subsections on the Capacitated Arc Routing Problem (CARP) and then delves into several variants of multiple ARPs, ending with GRPs and problems with profits. Section 4 is devoted to applications, including distribution and collection routes, outdoor activities, post-disaster operations, road cleaning and marking. As new applications emerge and existing applications continue to be used and adapted, the future of arc routing research looks promising.info:eu-repo/semantics/publishedVersio

    Arc Routing Problems for Road Network Maintenance

    Get PDF
    RÉSUMÉ : Cette thĂšse prĂ©sente deux problĂšmes rencontrĂ©s dans l’entretien des rĂ©seaux routiers, soit la surveillance des rĂ©seaux routiers pour la dĂ©tection de verglas sur la chaussĂ©e et la reprogrammation des itinĂ©raires pour les activitĂ©s de dĂ©neigement et d’épandage de sel. Nous reprĂ©sentons ces problĂšmes par des modĂšles de tournĂ©es sur les arcs. La dĂ©pendance aux moments et la nature dynamique sont des caractĂ©ristiques propres de ces problĂšmes, par consĂ©quence le cas de surveillance des rĂ©seaux routiers est modĂ©lisĂ© comme un problĂšme de postier rural avec fenĂȘtres-horaires (RPPTW), tandis que le cas de la reprogrammation utilise des modĂšles obtenus Ă  partir des formulations de problĂšmes de tournĂ©es sur les arcs avec capacitĂ©. Dans le cas du problĂšme de surveillance, une patrouille vĂ©rifie l’état des chemins et des autoroutes, elle doit principalement dĂ©tecter le verglas sur la chaussĂ©e dans le but d’assurer de bonnes conditions aux chauffeurs et aux piĂ©tons. Étant donnĂ© un rĂ©seau routier et des prĂ©visions mĂ©tĂ©o, le problĂšme consiste Ă  crĂ©er une tournĂ©e qui permette de dĂ©tecter opportunĂ©ment le verglas sur les rues et les routes. L’objectif poursuivi consiste Ă  minimiser le coĂ»t de cette opĂ©ration. En premier, on prĂ©sente trois formulations basĂ©es sur la programmation linĂ©aire en nombres entiers pour le problĂšme de surveillance des rĂ©seaux qui dĂ©pend du moment et deux mĂ©thodes de rĂ©solution: un algorithme de coupes et un algorithme heuristique appelĂ© adaptive large neighborhood search (ALNS). La mĂ©thode exacte inclut des inĂ©quations valides tirĂ©es du problĂšme du voyageur de commerce avec fenĂȘtres-horaires et aussi du problĂšme de voyageur du commerce avec contraintes de prĂ©cĂ©dence. La mĂ©thode heuristique considĂšre deux phases: en premier, on trouve une solution initiale et aprĂšs dans la deuxiĂšme phase, l’algorithme essaie d’amĂ©liorer la solution initiale en utilisant sept heuristiques de destruction et deux heuristiques de rĂ©paration choisies au hasard. La performance des heuristiques est Ă©valuĂ©e pendant les itĂ©rations. Une meilleure performance correspond Ă  une plus grande probabilitĂ© de choisir une heuristique. Plusieurs tests ont Ă©tĂ© faits sur deux ensembles d’exemplaires de problĂšmes. Les rĂ©sultats obtenus montrent que l’algorithme de coupes est capable de rĂ©soudre des rĂ©seaux avec 104 arĂȘtes requises et des fenĂȘtres-horaires structurĂ©es par tranches horaires ; l’algorithme peut aussi rĂ©soudre des rĂ©seaux avec 45 arĂȘtes requises et des fenĂȘtres-horaires structurĂ©es pour chaque arĂȘte requise. Pour l’algorithme ALNS, diffĂ©rentes versions de l’algorithme sont comparĂ©es. Les rĂ©sultats montrent que cette mĂ©thode est efficace parce qu’elle est capable de rĂ©soudre Ă  l’optimalitĂ© 224 des 232 exemplaires et de rĂ©duire le temps de calcul significativement pour les exemplaires les plus difficiles. La derniĂšre partie de la thĂšse introduit le problĂšme de la reprogrammation de tournĂ©es sur les arcs avec capacitĂ© (RCARP), lequel permet de modĂ©liser la reprogrammation des itinĂ©raires aprĂšs une panne d’un vĂ©hicule lors de la phase d’exĂ©cution d’un plan initial des activitĂ©s de dĂ©neigement ou d’épandage de sel. Le planificateur doit alors modifier le plan initial rapidement et reprogrammer les vĂ©hicules qui restent pour finir les activitĂ©s. Dans ce cas, l’objectif poursuivi consiste Ă  minimiser le coĂ»t d’opĂ©ration et le coĂ»t de perturbation. La distance couverte par les vĂ©hicules correspond au coĂ»t d’opĂ©ration, cependant une nouvelle mĂ©trique est dĂ©veloppĂ©e pour mesurer le coĂ»t de perturbation. Les coĂ»ts considĂ©rĂ©s sont des objectifs en conflit. On analyse quatre politiques Ă  la phase de re-routage en utilisant des formulations de programmation linĂ©aire en nombres entiers. On propose une solution heuristique comme mĂ©thode pour rĂ©soudre le RCARP quand les coĂ»ts d’opĂ©ration et de perturbation sont minimisĂ©s en mĂȘme temps et quand une rĂ©ponse rapide est nĂ©cessaire. La mĂ©thode consiste Ă  fixer une partie de l’itinĂ©raire initial et aprĂšs Ă  modifier seulement les itinĂ©raires des vĂ©hicules les plus proches de la zone de l’interruption de la tournĂ©e du vĂ©hicule dĂ©faillant. La mĂ©thode a Ă©tĂ© testĂ©e sur des exemplaires obtenus d’un rĂ©seau rĂ©el. Nos tests indiquent que la mĂ©thode peut rĂ©soudre rapidement des exemplaires avec 88 arĂȘtes requises et 10 vĂ©hicules actifs aprĂšs la panne d’un vĂ©hicule. En conclusion, la principale contribution de cette thĂšse est de prĂ©senter des modĂšles de tournĂ©es sur les arcs et de proposer des mĂ©thodes de rĂ©solution d’optimisation qui incluent la dĂ©pendance aux temps et l’aspect dynamique. On propose des modĂšles et des mĂ©thodes pour rĂ©soudre le RPPTW, et on prĂ©sente des rĂ©sultats pour ce problĂšme. On introduit pour la premiĂšre fois le RCARP. Trois articles correspondant aux trois principaux chapitres ont Ă©tĂ© acceptĂ©s ou soumis Ă  des revues avec comitĂ© de Lecture: “The rural postman problem with time windows” acceptĂ© dans Networks, “ALNS for the rural postman problem with time windows” soumis Ă  Networks, and “The rescheduling capacitated arc routing problem” soumis Ă  International Transactions in Operational Research.----------ABSTRACT : This dissertation addresses two problems related to road network maintenance: the road network monitoring of black-ice and the rescheduling of itineraries for snow plowing and salt spreading operations. These problems can naturally be represented using arc routing models. Timing-sensitive and dynamic nature are inherent characteristics of these problems, therefore the road network monitoring is modeled as a rural postman problem with time windows (RPPTW) and in the rescheduling case, models based on capacitated arc routing formulations are suggested for the rerouting phase. The detection of black-ice on the roads is carried out by a patrol to ensure safety conditions for drivers and pedestrians. Specific meteorological conditions cause black-ice on the roads; therefore the patrol must design a route covering part of the network in order to timely detect the black-ice according to weather forecasts. We look for minimum-cost solutions that satisfy the timing constraints. At first, three formulations based on mixed integer linear programming are presented for the timing-sensitive road network monitoring and two solution approaches are proposed: a cutting plane algorithm and an adaptive large neighborhood search (ALNS) algorithm. The exact method includes valid inequalities from the traveling salesman problem (TSP) with time windows and from the precedence constrained TSP. The heuristic method consists of two phases: an initial solution is obtained, and then in the second phase the ALNS method tries to improve the initial solution using seven removal and two insertion heuristics. The performance of the heuristics is evaluated during the iterations, and therefore the heuristics are selected depending on their performance (with higher probability for the better ones). Several tests are done on two sets of instances. The computational experiments performed show that the cutting plane algorithm is able to solve instances with up to 104 required edges and with time windows structured by time slots, and problems with up to 45 required edges and time windows structured by each required edge. For the ALNS algorithm, several versions of the algorithm are compared. The results show that this approach is efficient, solving to optimality 224 of 232 instances and significantly reducing the computational time on the hardest instances. The last part of the dissertation introduces the rescheduling capacitated arc routing problem (RCARP), which models the rescheduling of itineraries after a vehicle failure happens in the execution of an initial plan of snow plowing or salt spreading operations. A dispatcher must quickly adjust the remaining vehicles and modify the initial plan in order to complete the operations. In this case we look for solutions that minimize operational and disruption costs. The traveled distance represents the operational cost, and a new metric is discussed as disruption cost. The concerned objectives are in conflict. Four policies are analyzed in the rerouting phase using mixed integer linear programming formulations. A heuristic solution is developed to solve the RCARP when operational and disruption costs are minimized simultaneously and a quick response is needed. The idea is to fix part of the initial itinerary and only modify the itinerary of vehicles closer to the failure zone. The method is tested on a set of instances generated from a real network. Our tests indicate that the method can solve instances with up to 88 required edges and 10 active vehicles after the vehicle breakdown. In short the main contribution of this dissertation is to present arc routing models and optimization solution techniques that consider timing-sensitive and dynamic aspects. Formulations and solution methods with computational results are given for the RPPTW, and the RCARP is studied for the first time here. Three articles corresponding to the main three chapters have been accepted or submitted to peer review journals: “The rural postman problem with time windows” accepted in Networks, “ALNS for the rural postman problem with time windows” submitted to Networks, and “The rescheduling capacitated arc routing problem” submitted to International Transactions in Operational Research

    Efficient routing of snow removal vehicles

    Get PDF
    This research addresses the problem of finding a minimum cost set of routes for vehicles in a road network subject to some constraints. Extensions, such as multiple service requirements, and mixed networks have been considered. Variations of this problem exist in many practical applications such as snow removal, refuse collection, mail delivery, etc. An exact algorithm was developed using integer programming to solve small size problems. Since the problem is NP-hard, a heuristic algorithm needs to be developed. An algorithm was developed based on the Greedy Randomized Adaptive Search Procedure (GRASP) heuristic, in which each replication consists of applying a construction heuristic to find feasible and good quality solutions, followed by a local search heuristic. A simulated annealing heuristic was developed to improve the solutions obtained from the construction heuristic. The best overall solution was selected from the results of several replications. The heuristic was tested on four sets of problem instances (total of 115 instances) obtained from the literature. The simulated annealing heuristic was able to achieve average improvements of up to 26.36% over the construction results on these problem instances. The results obtained with the developed heuristic were compared to the results obtained with recent heuristics developed by other authors. The developed heuristic improved the best-known solution found by other authors on 18 of the 115 instances and matched the results on 89 of those instances. It worked specially better with larger problems. The average deviations to known lower bounds for all four datasets were found to range between 0.21 and 2.61%

    Integrated network routing and scheduling problem for salt trucks with replenishment before snowfall

    Get PDF
    Kar yaÄŸÄ±ĆŸÄ± öncesinde ve sırasında yolların zamanında tuzlanması, trafik gĂŒvenliğini iyileƟtirmek ve trafik sıkÄ±ĆŸÄ±klığını önlemek için önemli bir önleyici faaliyettir. Bu çalÄ±ĆŸmada, bir Ɵehir yolu ağındaki tuz kamyonlarının rotalama ve çizelgeleme problemi ele alınmÄ±ĆŸtır. Ele alınan problem Ä°stanbul BĂŒyĂŒkƟehir Belediyesinin yoğun kar yaÄŸÄ±ĆŸÄ± durumlarında karĆŸÄ±laƟtığı bir operasyonel problemdir ve periyodik olarak çözĂŒlmelidir. Problemde, araç filosu tuz kapasitesi açısından heterojen araçlardan oluƟmaktadır ve birden fazla tuz ikmal noktası bulunmaktadır. Hava Ɵartları gerektirdiğinde, tuzlanması gereken yollar ve bu yollar için öncelik seviyeleri belirlenmektedir. Amaç, ağın farklı noktalarında konumlanmÄ±ĆŸ olan araçların, tuzlanması gereken tĂŒm yolları tuzlayacak Ɵekilde ve yolların ağırlıklı tamamlanma sĂŒresini en kĂŒĂ§ĂŒkleyerek rotalanması ve çizelgelenmesidir. Tuza ihtiyacı olan her yol tek bir araç tarafından tuzlanmalıdır. Araçlar tuzlanması gereken bir yolu tuzlama yapmadan sadece geçiƟ yapmak amacıyla da kullanılabilir. Araçlar, tuzları bittiğinde tuz ikmal noktalarını ziyaret etmelidir. Problemin çözĂŒmĂŒ için ilk olarak bir karma tam sayılı programlama modeli geliƟtirilmiƟtir. Problem bĂŒyĂŒklĂŒÄŸĂŒ arttıkça modelin performansının hızla dĂŒĆŸtĂŒÄŸĂŒ gözlemlenmiƟ ve iki aƟamalı bir sezgisel yöntem geliƟtirilmiƟtir. Sezgiselin ilk aƟamasında yapıcı algoritma ile olurlu bir baƟlangıç çözĂŒmĂŒ elde edilmektedir, ikinci aƟamasında bulunan baƟlangıç çözĂŒmĂŒ bir komƟuluk arama algoritması ile geliƟtirilmektedir. ÇözĂŒm yaklaĆŸÄ±mımızın verimliliği, gerçek hayat yol ağlarını yansıtan rastgele oluƟturulmuƟ örnekler ĂŒzerinde analiz edilmiƟtir.Timely salting of roads before the snowfall is an important preventive activity for improving traffic safety and avoiding traffic congestions. We study the problem of routing and scheduling of salt trucks on a city road network. The problem is motivated by the operational problem that the Istanbul Metropolitan Municipality face in case of a heavy snowfall, and thereby should be solved in a periodic manner.In this problem, the vehicle fleet consists of heterogeneous vehicles that differ in salt capacity and there are multiple salt replenishment points. At the beginning of the current planning horizon, given a set of salt needing roads with different urgency levels, the vehicles start from different points of the network (i.e., their final locations at the end of the former planning horizon) and should cover all salt needing roads with the objective of minimizing the total weighted completion time of salting operation of each service needing arc. Each service needing arc should be serviced by exactly one vehicle, however, can be traversed for deadheading by a vehicle as part of its route.Vehicles visit replenishment points when they run out of salt. We first develop a Mixed-Integer Programming model for the problem. Since the performance of the model degrades rapidly as the problem size increases, we propose a simulated annealing metaheuristic, which obtains an initial solution by a constructive heuristic in the first phase, and then improves the solution in the next phase. The efficiency of our solution approach is evaluated on randomly generated instances reflecting real life road networks

    Algoritmos e formulaçÔes matemåticas para problemas de roteamento em arcos

    Get PDF
    Orientador: FĂĄbio Luiz UsbertiTese (doutorado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Problemas de roteamento em arcos tĂȘm por objetivo determinar rotas de custo mĂ­nimo que visitam um subconjunto de arcos de um grafo, com uma ou mais restriçÔes adicionais. Esta tese estuda trĂȘs problemas NP-difĂ­ceis de roteamento em arcos: (1) o problema de roteamento em arcos capacitado (CARP); (2) o problema de roteamento em arcos capacitado e aberto (OCARP); e (3) o problema do carteiro chinĂȘs com cobertura (CCPP). Apresentamos formulaçÔes matemĂĄticas e mĂ©todos exatos e heurĂ­sticos para tratar computacionalmente esses problemas: (i) uma heurĂ­stica construtiva gulosa e randomizada Ă© proposta para o CARP; (ii) uma metaheurĂ­stica de algoritmos genĂ©ticos hĂ­brido e dois mĂ©todos de limitantes inferiores por programação linear inteira, um branch-and-cut e um baseado em redes de fluxos, sĂŁo propostos para o OCARP; e (iii) um mĂ©todo exato branch-and-cut com desigualdades vĂĄlidas e uma heurĂ­stica construtiva sĂŁo propostos para o CCPP. Extensivos experimentos computacionais utilizando instĂąncias de benchmark foram executados para demonstrar o desempenho dos mĂ©todos propostos em relação aos mĂ©todos da literatura, considerando tanto a qualidade das soluçÔes obtidas quanto o tempo de processamento. Nossos resultados mostram que os mĂ©todos propostos sĂŁo estado da arte. Os problemas estudados apresentam aplicaçÔes prĂĄticas relevantes: o CARP tem aplicaçÔes em coleta de lixo urbano e remoção de neve de estradas; o OCARP tem aplicaçÔes em roteamento de leituristas e na definição de caminhos de corte em chapas metĂĄlicas; e o CCPP tem aplicaçÔes em roteamento de leituristas com o uso de tecnologia wireless. A solução desses problemas remete Ă  diminuição de custos logĂ­sticos, melhorando a competitividade das empresasAbstract: Arc routing problems aim to find minimum cost routes that visit a subset of arcs of a graph, with one or more side constraints. This thesis studies three NP-hard arc routing problems: (1) the capacitated arc routing problem (CARP); (2) the open capacitated arc routing problem (OCARP); and (3) the covering Chinese postman problem (CCPP). We present mathematical formulations and heuristic and exact methods to computationally solve these problems: (i) a greedy and randomized constructive heuristic is proposed for the CARP; (ii) a hybrid genetic algorithm metaheuristic and two linear integer programming lower bound methods, one based on branch-and-cut and one based on flow networks, are proposed for the OCARP; and (iii) an exact branch-and-cut method with valid inequalities and a constructive heuristic are proposed for the CCPP. Extensive computational experiments using benchmark instances were performed to demonstrate the performance of the proposed methods in comparison to the previous methods, regarding both quality of solutions and processing time. Our results show that the proposed methods are state-of-the-art. The studied problems have many relevant practical applications: the CARP has applications on urban waste collection and snow removal; the OCARP has applications on the routing of meter readers and the cutting of metal sheets; and last, the CCPP has applications on automated meter readers routing. The solution of these problems leads to the reduction of logistics costs, improving businesses competitivenessDoutoradoCiĂȘncia da ComputaçãoDoutor em CiĂȘncia da Computação2016/00315-0FAPES

    A concise guide to existing and emerging vehicle routing problem variants

    Get PDF
    Vehicle routing problems have been the focus of extensive research over the past sixty years, driven by their economic importance and their theoretical interest. The diversity of applications has motivated the study of a myriad of problem variants with different attributes. In this article, we provide a concise overview of existing and emerging problem variants. Models are typically refined along three lines: considering more relevant objectives and performance metrics, integrating vehicle routing evaluations with other tactical decisions, and capturing fine-grained yet essential aspects of modern supply chains. We organize the main problem attributes within this structured framework. We discuss recent research directions and pinpoint current shortcomings, recent successes, and emerging challenges

    Optimisation de tournées de véhicules en viabilité hivernale

    Get PDF
    RÉSUMÉ : Cette thĂšse dĂ©veloppe des outils mathĂ©matiques et informatiques pour amĂ©liorer les opĂ©rations de viabilitĂ© hivernale. En particulier, la confection des tournĂ©es de dĂ©neigement est traitĂ©e comme un problĂšme de tournĂ©es sur les arcs avec plusieurs contraintes. Une mĂ©taheuristique est d’abord dĂ©veloppĂ©e pour la confection de ces tournĂ©es. Par la suite, des modifications majeures sont apportĂ©es Ă  cet algorithme pour tenir compte des caractĂ©ristiques spĂ©cifiques aux problĂšmes de tournĂ©es sur les arcs (arc routing problem) (ARP) sur des rĂ©seaux routiers rĂ©els. Finalement, un second problĂšme combinant les tournĂ©es de dĂ©neigement et d’épandage avec la mise en commun de certains vĂ©hicules pour les opĂ©rations est traitĂ©. La solution dĂ©veloppĂ©e permet de tirer parti des caractĂ©ristiques de chaque vĂ©hicule. Tout au long de la thĂšse, un accent particulier est portĂ© sur l’utilisation des donnĂ©es rĂ©elles ainsi que sur le dĂ©veloppement de mĂ©thodes pour faciliter l’importation et l’exportation de ces donnĂ©es. Les travaux entourant cette thĂšse dĂ©butent avec la confection de tournĂ©es de dĂ©neigement pour une ville au QuĂ©bec, soit Dolbeau-Mistassini (DM). De nombreux problĂšmes ont Ă©tĂ© rencontrĂ©s avec l’utilisation d’une mĂ©thode tirĂ©e de la littĂ©rature. Parmi ceux-ci, on compte : — de nombreux demi-tours difficiles Ă  exĂ©cuter par les vĂ©hicules ; — le faible respect des prioritĂ©s accordĂ©es aux rues Ă  l’échelle du rĂ©seau ; — de nombreux vĂ©hicules parcourent de longues distances pour se rendre dans les coins reculĂ©s du rĂ©seau ; — le dĂ©sĂ©quilibre des tĂąches de travail en raison des diffĂ©rentes vitesses d’opĂ©ration des vĂ©hicules ; — le fait que la mĂ©thode ne tient pas compte des ruelles qui peuvent ĂȘtre traitĂ©es dans une direction ou dans l’autre en un seul passage. À la suite de nombreux ajustements manuels pour corriger les tournĂ©es obtenues, force a Ă©tĂ© de constater que des amĂ©liorations pouvaient ĂȘtre apportĂ©es Ă  ce type de mĂ©thode. Les travaux concernant la premiĂšre contribution de cette thĂšse ont donc portĂ© sur le dĂ©veloppement d’une mĂ©thode de crĂ©ation de tournĂ©es de dĂ©neigement. En raison du grand nombre de variables et de contraintes considĂ©rĂ©es dans le problĂšme, le choix s’est portĂ© sur une mĂ©thode heuristique. Ce type de mĂ©thode offre un bon Ă©quilibre entre le temps de traitement et la qualitĂ© des solutions obtenues. Plus prĂ©cisĂ©ment, le choix s’est arrĂȘtĂ© sur une mĂ©taheuristique de type algorithme de recherche Ă  voisinage adaptatif large (adaptive large neighborhood search) (ALNS), en raison du succĂšs remportĂ© rĂ©cemment par ce type de mĂ©thode. Le premier article a permis de constater que l’algorithme dĂ©veloppĂ© permet de crĂ©er des tournĂ©es pour les vĂ©hicules de dĂ©neigement. Les contraintes suivantes sont respectĂ©es : Ă©quilibrage des tournĂ©es, couverture partielle du rĂ©seau, vitesses hĂ©tĂ©rogĂšnes, restrictions de virages, restrictions rue/vĂ©hicule et hiĂ©rarchie du rĂ©seau. Pour la deuxiĂšme contribution de thĂšse, le problĂšme a d’abord Ă©tĂ© formalisĂ© par l’intermĂ©diaire d’un programme linĂ©aire en nombres entiers (mixed integer programming) (MIP). Le problĂšme a Ă©tĂ© formulĂ© comme un problĂšme des k-postiers ruraux avec objectif minmax (min-max k-vehicles rural postman problem) (MM K-RPP) avec hiĂ©rarchies, pĂ©nalitĂ©s sur virages, vitesses d’opĂ©ration hĂ©tĂ©rogĂšnes et tournĂ©es ouvertes sur un graphe mixte. Tel qu’anticipĂ©, la rĂ©solution devient rapidement impossible Ă  traiter avec un solveur commercial en utilisant seulement 20 segments de rue. Il a Ă©tĂ© dĂ©cidĂ© de poursuivre l’approfondissement de l’algorithme dĂ©veloppĂ© en premiĂšre partie. Cette dĂ©cision a Ă©tĂ© prise notamment en raison du trĂšs long temps de traitement qui rĂ©duit l’utilitĂ© du premier algorithme. Cette dĂ©cision repose aussi sur le fait que visuellement, on constate que les tournĂ©es obtenues peuvent ĂȘtre amĂ©liorĂ©es. Dans cette optique, une collaboration a Ă©tĂ© initiĂ©e avec messieurs Fabien LehuĂ©dĂ© et Olivier PĂ©ton du laboratoire des sciences du numĂ©rique de Nantes (LS2N) Ă  IMT Atlantique. Leur expertise avec la mĂ©thode ALNS a effectivement permis d’amĂ©liorer grandement les rĂ©sultats obtenus. Parmi les amĂ©liorations apportĂ©es, on note une transformation du rĂ©seau permettant de tenir compte des pĂ©nalitĂ©s sur virages lors du calcul des plus courts chemins. Cette transformation permet Ă©galement de mieux prendre en compte les ruelles qui requiĂšrent un seul passage dans une direction ou dans l’autre. De plus, la possibilitĂ© d’appliquer plusieurs fois un opĂ©rateur de destruction avant de passer Ă  la construction est ajoutĂ©e. Cette contribution a Ă©galement Ă©tĂ© l’occasion de dĂ©velopper et tester de nouveaux opĂ©rateurs de voisinage, dĂ©velopper une mĂ©thode de groupement des arcs et revoir et simplifier le code de la mĂ©taheuristique. L’algorithme a Ă©tĂ© appliquĂ© Ă  la premiĂšre Ă©tude de cas ainsi qu’a deux nouvelles Ă©tudes de cas, Baie-Comeau (BC) et Plateau-Mont-Royal (PMR). Des tests ont Ă©galement Ă©tĂ© exĂ©cutĂ©s en comparant les nouvelles tournĂ©es obtenues Ă  des tournĂ©es conçues quelques annĂ©es plus tĂŽt ainsi qu’aux rĂ©sultats obtenus par un solveur commercial. Les rĂ©sultats obtenus dĂ©montrent que la mĂ©thodologie amĂ©liore les tournĂ©es conçues prĂ©cĂ©demment. Il est aussi possible de conclure que la mĂ©thode de groupage des arcs amĂ©liore la qualitĂ© des solutions obtenues et l’efficacitĂ© des nouveaux opĂ©rateurs dĂ©veloppĂ©s varie selon le rĂ©seau utilisĂ©. Pour la troisiĂšme contribution, nous sommes revenus sur le cas d’étude initial tel que dĂ©crit par les intervenants de la premiĂšre Ă©tude de cas. Il a Ă©tĂ© dit que les charges de travail doivent ĂȘtre Ă©quilibrĂ©es, mais que certains vĂ©hicules doivent Ă©galement Ă©pandre des fondants ou des abrasifs en plus de dĂ©neiger. Pour tenir compte de cette contrainte, certaines tournĂ©es avaient dĂ©libĂ©rĂ©ment Ă©tĂ© gardĂ©es plus courtes dans les premiĂšres solutions. Pour le troisiĂšme article, il a Ă©tĂ© dĂ©cidĂ© de traiter cette problĂ©matique de front. Ce qu’il faut savoir est que certains vĂ©hicules sont Ă©quipĂ©s pour l’épandage et le dĂ©neigement alors que d’autres sont Ă©quipĂ©s pour le dĂ©neigement seulement. Lorsque les premiers traitent un segment de rue, ils exĂ©cutent les deux opĂ©rations simultanĂ©ment. Lorsque les deuxiĂšmes traitent un segment de rue, il faut planifier un second passage par les premiers vĂ©hicules pour qu’ils puissent Ă©pandre des fondants ou des abrasifs. L’algorithme dĂ©veloppĂ© prĂ©cĂ©demment a donc Ă©tĂ© modifiĂ© dans cette optique. En plus, la considĂ©ration des contraintes de restrictions rue/vĂ©hicule a Ă©tĂ© ajoutĂ©e dans l’algorithme. Les rĂ©sultats dĂ©montrent que l’algorithme permet effectivement de concevoir des tournĂ©es qui respectent les contraintes de la nouvelle Ă©tude de cas. Cet outil permet donc de tirer profit de l’interaction entre les divers types de vĂ©hicules. La contribution souligne Ă©galement l’utilitĂ© d’un tel outil pour supporter l’analyse des besoins justifiant l’achat de nouveaux vĂ©hicules. En parallĂšle aux dĂ©veloppements algorithmiques, des mĂ©thodes d’importation et d’exportation des donnĂ©es provenant des cas d’étude rĂ©els sont aussi dĂ©veloppĂ©es. DĂšs le dĂ©part, il a Ă©tĂ© choisi d’utiliser des fichiers de type Shapefile comme source de donnĂ©es en raison de sa grande disponibilitĂ© et de la compatibilitĂ© avec les systĂšme d’information gĂ©ographique (SIG). Une mĂ©thode pour passer du rĂ©seau gĂ©ographique vers un rĂ©seau mathĂ©matique a donc Ă©tĂ© amĂ©liorĂ©e au cours des travaux. Alors qu’au dĂ©but des travaux de la thĂšse, il fallait passer par un chiffrier Microsoft ExcelTM pour ensuite importer les donnĂ©es dans le code, Ă  la fin, une mĂ©thode automatisĂ©e permet l’importation directe Ă  partir des fichiers Shapefiles vers le code de la mĂ©taheuristique. Quant aux rĂ©sultats obtenus, ils furent obtenus dans les premiĂšres Ă©tapes sous forment de reprĂ©sentations gĂ©ographiques dans un SIG ainsi que des feuilles d’instructions indiquant les Ă©tapes, coin de rue par coin de rue, aux opĂ©rateurs de vĂ©hicules. De ce cĂŽtĂ©, les dĂ©veloppements ont permis d’obtenir des fichiers de type KML. Ce type de fichier est compatible avec plusieurs logiciels et applications, dont Google EarthviewTM et des applications de guidage routier sur des appareils mobiles.----------ABSTRACT : In this thesis, we develop mathematical and computerized tools to improve winter viability operations. More precisely, the snow routing design problem is treated as an problĂšme de tournĂ©e sur les arcs (arc routing problem) (ARP). In a first effort to solve the problem, a metaheuristic procedure is designed. Then, some major modifications are made to the algorithm to improve the consideration of specific characteristics of real road networks. Finally, a second problem combining the routing of the snowplow and the spreading vehicles are addressed. The objective is to fully take advantage of the characteristics of the different type of vehicles. In parallel with the algorithmic development, this thesis also develops some methodologies to facilitate the importation and exportation of the real world data. Works concerning this thesis were initiated with a mandate to design snowplow routes for a city in the province of QuĂ©bec, namely DM. The problem was addressed by using a methodology found in the literature, however, several difficulties were encountered. Among others: — the routes contained several U-turns which are difficult to perform by the snow plowing vehicles; — little consideration of the priorities at the network level; — several vehicles have to travel to some remote streets in the same sector of the city where we would expect only one vehicle to go; — unbalanced sectors due to the different speeds of operation of the vehicles; — no consideration for back alleys that needs to be serviced only once in either direction. In respond to these problems, several manual modifications of the routes were undertaken to make them feasible. It was found that the methodology fails to solve the problem as it is encountered. Therefore, works concerning the first contribution of this thesis focused on the development of a methodology to design snowplow routing. Due to numerous variables and constraints, it was decided to develop a metaheuristic algorithm. This type of methodology offers a good balance between runtime and the quality of the solution obtained. In particular, an ALNS is selected because of its recent success cited in the literature. Thus, the first article concludes that the algorithm can design snowplow routing. The following constraints are considered: workload balance, partial area coverage, heterogeneous vehicle speeds, road/vehicle dependencies, network hierarchies and turn restrictions. In the second contribution of this thesis, the problem was modeled as a mixed integer program. It is formulated as a min-max k-rural postmen problem with hierarchies, turn penalties, open tours and heterogeneous speed on a mixed graph. As expected, the formulation is intractable even for a number of arcs as low as 20. It was then decided to pursue the development of the ALNS algorithm. This decision was taken considering the long runtime of the first algorithm and the fact that the routes obtained can be visually improved. A collaboration with Fabien LehuĂ©dĂ© and Olivier PĂ©ton from the Laboratoire des Sciences du NumĂ©rique de Nantes (LS2N), IMT Atlantique was undertaken. Their expertise with ALNS greatly helped to improve the results obtained. Among other improvements brought to the algorithm, one can cite the transformation of the graph which allows to better take into account turn penalties during the computation of the shortest paths. This transformation also allows to better take into account the back alleys which only need one service in either direction. This contribution also allowed to develop and test new neighborhood operators and an arc grouping methodology. Both of these innovations improve the quality of the solutions obtained. However the efficiency of the new operators varies with the network. For the third contribution, we took back the case study as it was described by the collaborator in DM. It was said that the workload needs to be balanced among the vehicles. However some vehicles must also perform winter spreading in addition to plowing. For the first set of routes produced, some of the routes were deliberately left with a lower workload to allow them to perform winter spreading. For the third article, it was decided to consider the spreading and the plowing directly during the construction and the improvement steps. Thus this problem was tackled more directly in the third article. It must be noted that some vehicles are equipped to perform both winter spreading and snow plowing and some others can only perform plowing. When the former service a street, they can perform both plowing and spreading at the same time. When the latter service a street, a second passage is required to spread salt or abrasives. The algorithm developed for the second contribution was then adapted for this new problem. Moreover, the street/vehicle restriction constraints were also added. The result shows that the algorithm can produce a set of routes respecting the constraints of the new problem. It can take advantage of the interaction between the various types of vehicles. The article also shows that such tool can be beneficial in analyzing the requirements for new vehicles. In parallel with the development of the algorithms, data importation and exportation techniques from real road networks are also developed. It was chosen to use Shapefiles because of its good relative availability and because of its compatibility with Geographic Information System (GIS). A method to transfer from a geographical to a mathematical network is improved during the thesis. At the beginning, a Microsoft ExcelTM datasheet is used to transfer the data from the GIS to the metaheuristic. At the end, it is possible to fetch the data directly from the Shapefiles to the metaheuristic. As for the results obtained, at the beginning, they were provided in the form of a Shapefile for visualization and indications on sheets of paper for the operators. At the end, the results can be exported to the KML format. This type of file is compatible with several software such as Google EarthviewTM and application Global Positioning System (GPS) applications on mobile devices

    A concise guide to existing and emerging vehicle routing problem variants

    Get PDF
    Vehicle routing problems have been the focus of extensive research over the past sixty years, driven by their economic importance and their theoretical interest. The diversity of applications has motivated the study of a myriad of problem variants with different attributes. In this article, we provide a concise overview of existing and emerging problem variants. Models are typically refined along three lines: considering more relevant objectives and performance metrics, integrating vehicle routing evaluations with other tactical decisions, and capturing fine-grained yet essential aspects of modern supply chains. We organize the main problem attributes within this structured framework. We discuss recent research directions and pinpoint current shortcomings, recent successes, and emerging challenges.</p
    • 

    corecore