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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Modelos de carregamento de cargas em veículos de distribuição e os impactos na produtividade das entregas e no nível de serviço

Silva, Emerson William da 20 May 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The supply chain is broad and includes actions that must serve customers quickly, safely and cost . However , the lack of planning to meet these actions causes a lot of quality in service delivery is compromised , which leads to dissatisfaction for the end consumer. One of the biggest impacts on the speed of deliveries by delivery vehicles is the provision of loading into the trunk , ie , how much easier is access to goods , the faster delivery and, thus , more customers can be served in the same time; which will certainly lead to greater vehicle productivity in number of deliveries per day . This work shows the two main models used in vehicle loading attacked distributors and their impact on delivery time and , as a consequence , the speed to serve customers . A technique for the study of linear two charging models for a company of urban and interurban freight distribution with data from 2006 schedule was used . The results indicate that the loading model with separation of cargoes city is more productive than the most commonly used model , without any kind of separation . It is hoped that this work will assist distribution companies in the speed of customer service and improving the service level of the supply chain . / A cadeia de suprimentos é ampla e envolve ações que devem atender os clientes com rapidez, segurança e baixo custo. Porém, a falta de planejamento para cumprir com essas ações faz com que muito da qualidade na prestação do serviço seja comprometida, o que gera insatisfação para o consumidor final. Um dos maiores impactos na rapidez das entregas por veículos de distribuição é a disposição do carregamento dentro do baú, ou seja, quanto mais fácil for o acesso às mercadorias, mais rápido será a entrega e, com isso, mais clientes poderão ser atendidos no mesmo período de tempo; o que certamente implicará em uma maior produtividade do veículo em número de entregas por dia. Este trabalho mostra os dois principais modelos de carregamento de veículos utilizados em atacados distribuidores e seus impactos no tempo de entrega e, como consequência, a rapidez em atender os clientes. Foi utilizada uma técnica de programação linear para o estudo de dois modelos de carregamento para uma empresa de distribuição urbana e interurbana de mercadorias com dados do ano de 2006. Os resultados encontrados indicam que o modelo de carregamento com separação por cidade das cargas é mais produtivo que o modelo mais comumente usado, sem qualquer tipo de separação. Espera-se que este trabalho auxilie as empresas distribuidoras na rapidez de atendimento aos clientes e na melhoria a do nível de serviço da cadeia de suprimentos. / Mestre em Engenharia Civil
22

Analysis of Single Echelon Logistics Model for Delivering Temperature Sensitive E-groceries in Cities using Electric Vehicle

Narayanasamy, Harivignesh January 2022 (has links)
With the increase in the growth of the e-commerce sector since the past decade, the pressure has been progressively more applied to the operations and supply chain. As the pandemic has pushed the companies to provide services at the customer doorstep due to the difficulties in accessing services from brick-and-mortar stores, the logistical operation of the companies is continuously put under pressure. Though the performance aspect of the supply chain operations is achieved as per company’s objectives, the sustainability part is always overlooked. For any logistics provider, the last mile is considered as one of the main deterrents in their supply chain operations. Some of the main factors include performance of the distribution process, delivery time window, level of service, congestion in the urban area, etc. The above and some other factors make it extremely difficult for the logistics provider to be sustainable in their operations.  There is a growing interest among the logistics provider to use electric vehicles in urban logistics. In particular, light electric vehicles are considered to be a valid alternate for fossil fuel powered sprinters or vans. The purpose of the study is to identify the logistical, technological and infrastructural challenges associated with implementing electric vehicles with refrigeration system in delivering e-groceries in cities. The thesis follows the methodology of collecting data from developed electric vehicle and analysing the data to identify the feasibility of implementing electromobility in last mile delivery. In order to identify the commercial application of electromobility, the collected data is applied in the developed simulation model. The scenario-based analysis has been used in the data collection and in simulation modelling experimentation. The scenario analysis has been used to have an in-depth understanding of all the possible outcomes. The results from the test observations provided data for further studies while the results from simulation modeling presented evidence for the effective application of electric vehicles in delivering e-groceries in last-mile. The comparison of electric vehicle (EV) with fossil fuel powered vehicle provided the strong performance of EV’s in terms of environmental, operational, and socio-economic aspects. The thesis provides new knowledge in the area of electromobility in last-mile research and also proposes potential future work which will be assisting the forthcoming research in advancing the boundary of the research topic. / Med den ökade tillväxten inom e-handelssektorn sedan det senaste decenniet har trycket successivt applicerats mer på verksamheten och leveranskedjan. Eftersom pandemin har drivit företagen att tillhandahålla tjänster utanför kunddörren på grund av svårigheterna att få tillgång till tjänster från tegelbutiker, sätts företagens logistiska drift kontinuerligt under press. Även om prestandaaspekten av leveranskedjans verksamhet uppnås enligt företagetsmål, förbises alltid hållbarhetsdelen. För alla logistikleverantörer betraktas den sista milen som en av de främsta avskräckningarna i deras leveranskedja. Några av huvudfaktorerna inkluderar distributionsprocessens prestanda, leveranstidsfönster, servicenivå, trängsel i tätorten etc. Ovanstående och några andra faktorer gör det extremt svårt för logistikleverantören att vara hållbar i sin verksamhet.  Det finns ett växande intresse bland logistikleverantören att använda elfordon i stadslogistik. I synnerhet anses lätta elfordon vara ett giltigt alternativ för sprinter eller skåpbilar som drivs med fossila bränslen. Syftet med studien är att identifiera de logistiska, tekniska och infrastrukturella utmaningarna i samband med att implementera elfordon med kylsystem för att leverera e-livsmedel i städer. Avhandlingen följer metodiken för att samla in data från utvecklade elfordon och analysera data för att identifiera genomförbarheten av att implementera elektromobilitet i sista mils leverans. För att identifiera den kommersiella tillämpningen av elektromobilitet, tillämpas den insamlade informationen i den utvecklade simuleringsmodellen. Den scenariobaserade analysen har använts i datainsamlingen och i simuleringsmodellexperiment. Scenarioanalysen har använts för att få en fördjupad förståelse av alla möjliga utfall. Resultaten från testobservationerna gav data för ytterligare studier medan resultaten från simuleringsmodellering presenterade bevis för den effektiva tillämpningen av elfordon för att leverera e-livsmedel på sista milen. Jämförelsen av elfordon (EV) med fossilbränsledrivna fordon gav elbilarnas starka prestanda när det gäller miljömässiga, driftsmässiga och socioekonomiska aspekter. Avhandlingen ger ny kunskap inom området elektromobilitet inom forskning på sista milen och föreslår även potentiellt framtida arbete som kommer att hjälpa den kommande forskningen att flytta fram gränsen förforskningsämnet.
23

Vers une organisation globale durable de l’approvisionnement des ménages : bilans économiques et environnementaux de différentes chaînes de distribution classiques et émergentes depuis l’entrepôt du fournisseur jusqu’au domicile du ménage / Towards a global sustainable organisation of housholds

Ayadi, Abdessalem 26 September 2014 (has links)
La logistique urbaine, et celle du dernier kilomètre notamment, est un sujet de préoccupation majeure pour les villes d’aujourd’hui. Pour répondre à cette préoccupation, nous avons établi dans le chapitre introductif un historique de la problématique de la logistique urbaine pour mieux comprendre son développement au fil des années, permettant ainsi de déduire qu’il est fondamental d’étudier la globalité de la chaîne de distribution dans ce travail de thèse pour mieux résoudre la problématique de la logistique urbaine. En revanche, nous étions confrontés à un sujet redoutable par sa complexité et l’absence de données complètes et fiables. De plus, nous assistons dans les dernières années, à une multiplication des schémas logistiques que ce soit pour la livraison des magasins à partir des entrepôts des fournisseurs ou pour l’approvisionnement des clients à partir des surfaces de vente.De ce fait, nous avons fixé comme objectif d’identifier toutes les organisations logistiques existantes et émergentes en France et ailleurs (deux séjours d’un an en Angleterre et en Suisse). Pour ce faire, nous avons déterminé dans le deuxième chapitre les paramètres de différenciation des modes d’organisation en amont (de l’entrepôt du fournisseur à la surface de vente) et en aval de la chaîne (de la surface de vente au domicile du client). Or il n’existe pas aujourd’hui de bilan économique et environnemental complet permettant d’arbitrer entre différentes formes de distribution classiques et à distance en tenant compte des particularités des familles des produits (non alimentaires, secs, frais, surgelés) et de la diversité de leurs modes de livraison.Face à ces contraintes de taille, nous avons eu recours aux enquêtes de terrain dans ce travail de recherche, qui ont été l’occasion de nouer de très nombreux contacts avec les acteurs de la grande distribution, permettant ainsi de recueillir des données techniques et économiques de première main et inédites jusqu’ici. En plus de la résolution du verrou empirique dans le troisième chapitre, ce travail de thèse a permis également de lever des verrous méthodologiques relatifs à la reconstitution et à l’évaluation des coûts et des émissions logistiques (pour les entrepôts de stockage et les plateformes de transit en amont ; et pour les surfaces de vente et les plateforme de mutualisation en aval) et des coûts et des émissions des véhicules de transport (des articulés et des porteurs en amont ; et des VUL, voitures particulières, transports publics, deux roues, et marche à pied en aval). Enfin, ce travail de thèse a permis d’aboutir à la construction d’une base de données et la mise au point d’un outil d’aide à la décision permettant ainsi de déduire, dans le quatrième chapitre, les bilans économique et environnemental de la globalité de la chaîne depuis l’entrepôt du fournisseur jusqu’au domicile du ménage. Cet outil devrait se révéler très utile pour les politiques publiques, les stratégies futures des grands distributeurs et leurs prestataires logistiques afin de privilégier les modes d’organisation économes et durables, et même pour le client final afin d’estimer les coûts et les émissions de ses actes d’achat dans les différentes alternatives de vente classique et à distance. / Urban logistics and the last mile in particular, is a major concern for cities today. To address this concern, we have established in the introductory chapter a history of the problem of urban logistics. This allows a better understanding of its development over the years, and deducing that it’s essential to study the supply chain in its entirety to better solve the problem of urban logistics. However, we were faced with a daunting task: the lack of comprehensive and reliable data. In addition, there has been a multiplication of distribution channels in recent years. This includes the delivery from warehouses to stores and further to households from the retail space.Therefore, we intended to identify all existing and emerging logistics organizations in France and beyond (one year exchange stay in England and Switzerland for research purposes). To do this, we established in the second chapter certain parameters that differentiate the logistics modes of various organizations upstream (from manufacturers to retail stores) and downstream (from retail stores to households). Unfortunately, there does not exist any economic and environmental assessment to settle between different forms of traditional and modern electronic distribution, by taking into account the various characteristics of different products families (non-food, dry, fresh, frozen) and the diversity of their delivery modes.Faced with constraints of such size, we conducted surveys with different actors of distribution channels, which provided the opportunity to make contacts, thus collect firsthand and so far unpublished technical and economic data. In addition to the resolution of empirical inadequacy in the third chapter, this research also helped to develop a methodological approach related to the reconstruction and evaluation of logistics costs and emissions (in warehouses, transit platforms, retail stores and shared platforms) and also the costs and emissions of vehicles (trucks, delivery van, cars, public transport, bikes, motorbikes and walking).Finally, this research has lead to the construction of a database and the development of a decision support tool to infer, in the fourth chapter, the economic and environmental appraisal of the entire supply chain from the supplier's warehouse to the final customer. This tool can be useful for public policy, future strategies of retailers and Third-Party Logistics providers to focus on efficient and sustainable modes of organization, and even it will benefit the customer to estimate the costs and emissions of its acts of purchase in classic and e-grocery shopping.

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