[pt] As constantes mudanças no mercado levaram a um redirecionamento do foco empresarial para o consumidor final. Assim, as formas tradicionais de distribuição que empurravam a produção para o mercado, passaram a ser substituídas por novas formas onde o abastecimento é puxado pela necessidade de mercado. Entre estas novas formas de distribuição apresenta-se o sistema Cross Docking. Nesta dissertação, esse sistema será apresentado, buscando compreender sua estrutura e seus objetivos. O Cross Docking opera transferindo a mercadoria diretamente da área de recebimento para a área de embarque, sem armazená-la, buscando com isso oferecer melhores serviços e manter a oferta constante de produtos. Além disso, a pesquisa tem como objetivo identificar as vantagens e desvantagens do seu uso e os obstáculos de implementação. Será realizada também uma pesquisa de campo, onde uma observação simples da realidade terá como base a Empresa Brasileira de Correios e Telégrafos - ECT. Esta análise se deve ao fato da ECT operar de acordo com a filosofia do sistema Cross Docking, ou seja, as encomendas urgentes fluem pelo centro de distribuição, sendo imediatamente transferidas para as docas de expedição, sem paradas. Dessa forma, a pesquisa busca realizar um diagnóstico da distribuição utilizando-se como referência a ECT. Para essa empresa são avaliados tanto o seu desempenho operacional como a execução dos seus serviços de encomendas expressas, com base nos dois índices de performance utilizados pela própria empresa: produtividade e qualidade (nível de serviço). / [en] The frequent changes in the market turned any company`s focus to the final consumer. So, the ordinary distribution techniques, which usually pushed the production to the market, has being replaced by new techniques, where the product supplies are pulled by the market needs. One of these new ways of distribution is the Cross Docking system. This master`s thesis will present this system, in order to understand its structure and its aims. The Cross Docking concept immediately transfers the merchandise received at the point of reception, to the point of delivery, with the minimum time in between. So, this system can offer better service levels and keep a constant supply of products. In addition, this research has the purpose of identifying the main advantages and disadvantages derived from the use of this system and the main obstacles for its implementation. It will also make a field research, which will have the Empresa Brasileira de Correios e Telégrafos - ECT - as a basis for a simple observation of the reality. That is because the ECT operates with the same philosophy of the Cross Docking system, in which orders do not stay inside the Distribution Center but are immediately transferred to the outbound docks. So, this research has the purpose of diagnosing the distribution system, using the express services of ECT as the field research case study and the performance indexes such as, productivity and service level.

Bring Frigo transporterar och distribuerar kylda och frysta livsmedel inom Sverige och övriga Norden genom ett temperaturkontrollerat nätverk av fordon, kyllager, fryslager och terminaler. En av Bring Frigo:s terminaler är belägen i Linköping dit livsmedel som ska distribueras till eller från Östergötland ankommer för att lastas om mellan fjärr- och distributionsbilar. Idag räcker kapaciteten på terminalen i Linköping precis till för att kunna hantera det flöde av livsmedel som passerar genom terminalen. Då Bring Frigo nyligen ingått en affär med en större svensk matgrossist om att distribuera matgrossistens livsmedel inom Östergötland i sitt befintliga transportnätverk behöver terminalens kapacitet utökas för att detta ska vara möjligt. I samband med denna förändring vill Bring Frigo passa på att ta fram riktlinjer för hur omlastningsprocessen kan optimeras. Bring Frigo önskar erhålla riktlinjer för vart livsmedlen temporärt ska placeras inne i terminalen under omlastningsprocessen och hur lastbilar ska tilldelas lastkajer så att transportsträckan inne i terminalen hålls så kort som möjligt. Som ett första steg för att besvara var livsmedlen temporärt bör placeras inne i terminalen utformades en intern layout över den tilltänkta ombyggda terminalen. Därefter utvecklades och implementerades en heuristik som, utifrån den framtagna layouten och historiska data över livsmedelsflödet genom terminalen, tog fram var olika livsmedel temporärt bör placeras inne i terminalen och hur tilldelningen av lastkajer bör ske så att erfordrad transportsträcka hålls så kort som möjligt under omlastningsprocessen. Med hjälp av de resultat som erhölls från heuristiken formulerades specifika riktlinjer för respektive arbetsdag. Riktlinjerna för respektive dag delades vidare in i två olika nivåer beroende på om dagen kategoriserades som en dag med normal eller hög arbetsnivå utifrån totala antalet lastbärare som förväntas passera terminalen den aktuella dagen. Slutsatsen av studien är att de riktlinjer som utformats för omlastningsprocessen på terminalen bör reducera den erfordrade transportsträckan av livsmedel inne på terminalen och på så sätt effektivisera omlastningsprocessen, men att detta inte kan säkerställas i och med att historiska data använts som indata till heuristiken.

The current logistics chains must be designed to copy with short life cycles of products, high stock velocity, low degree of predictability etc. The conditions for accuracy, reliability and flexibility of deliveries at the markets have been changing, and that is why it is inevitable to seek new alternative methods that would lead to higher efficiency levels, remaining competitiveness and, at the same time, fulfil the needs and wishes of customers. In this paper I focuse on cross-docking which is a newer distribution method. In the first part of the paper, I try to determine the principles of this operation in distribution, identify individual types of cross-docking and in detail describe the assumptions and conditions under which the method should be implemented to reach the requested results. The paper then continues with an analysis of the current position of cross-docking and there are given several examples of demand driven supply chains that have been using this distribution method at a certain point. These examples are followed with a discussion on current options and problems of implementing cross-docking in the case of retailers and manufacturers.

Supply chain network design involves location decisions for production facilities and distribution centers. We consider a make-to-order supply chain environment where distribution centers serve as crossdocking terminals. Long waiting times may occur at a cross-docking terminal, unless sucient handling capacity is installed. In this study, we deal with a facility location problem with congestion eects at distribution centers. Along with location decisions, we make capacity allocation (service rate) and demand allocation decisions so that the total cost, including facility opening, transportation and congestion costs, is minimized. Response time to customer orders is a critical performance measure for a supply chain network. The decisions like where the plants and distribution centers are located aect the response time of the system. Response time is more sensitive to these decisions in a make-to-order business environment. In a distribution network where distribution centers function as cross-docking terminals, capacity or the service rate decisions also aect the response time performance. This study is closely related to a recent work Vidyarthi et al. (2009) which models distribution centers asM/G/1 queuing systems. They use the average waiting time formula ofM/G/1 queuing model. Thus, the average waiting time at a distribution center is a nonlinear function of the demand rate allocated to and the service rate available at the distribution center. The authors Vidyarthi et al. (2009) propose a linear approximation approach and a Lagrangian based heuristic for the problem. Dierent than the solution approach proposed in Vidyarthi et al. (2009), we propose a closed form formulation for the problem. In particular, we show that the waiting time function derived from M/G/1 queuing model can be represented via second order conic inequalities. Then, the problem becomes a mixed integer second order cone programming problem which can be solved by using commercial branch-and-bound software such as IBM ILOG CPLEX. Our computational tests show that proposed reformulation can be solved in reasonable CPU times for practical size instances.

Syfte – Rapportens syfte är att undersöka förbättringsmöjligheter av materialhantering mellan in-och utlastning på en cross-docking terminal. Baserat på syftet har två frågeställningar formulerats. Vilka aktiviteter ingår i materialhantering? Hur kan materialhanteringen effektiviseras? Metod – Studien har genomfört en förstudie på fallföretaget för att definiera ett problemområde. Utifrån problemområdet har syfte och frågeställningar formulerats. Fallstudien och litteraturgenomgång har genomförts parallellt för att skapa en abduktiv ansats. De inhämtade teorier från litteraturstudierna ligger stöd för det teoretiska ramverket.  Resultat – Flera slöserier identifierades under studien vilket påverkar den interna materialhanteringen. Inom de primära cross-docking aktiviteterna existerar slöserier vilket behöver elimineras för en effektivisering ska genomföras. Studien lyfter även vikten av ett fungerande informationsflöde för en effektiv materialhantering.  Implikationer – Eftersom problemområdet redan har etablerade teorier har ingen ny forskning genomförts. Däremot har studien inriktat sig på en annan synvinkel, där förhållandet mellan informationsflöde och materialflöde studerats.  Begränsningar – Begreppet materialhantering är brett och innefattar även materialhantering utanför terminalen. Rapporten har begränsat sig till enbart den interna materialhanteringen. Studien begränsar sig till enbart ett fallföretag vilket påverkar generaliserbarheten.  Nyckelord – Cross-docking, Materialhantering, Materialflöde, Informationsflöde.

No description available.

Dans une plateforme de cross-docking, les produits sont déchargés descamions entrants, triés puis directement rechargés dans les camions sortants– chaque produit passe moins de 24 heures sur la plateforme.L’analyse des écarts entre la littérature et les observations réalisées sur leterrain permet de dégager deux axes de recherche : la prise en compte desincertitudes opérationnelles d’une part, et de la capacité des ressourceshumaines de la plateforme d’autre part.Le problème de planification des camions entrants et sortants avec fenêtrede temps est modélisé par un programme linéaire et résolu par troisheuristiques différentes. La robustesse des plannings obtenus est ensuitetestée à l’aide d’un modèle de simulation à événements discrets, qui permetd’évaluer plusieurs reformulations robustes du modèle initial.Le problème de planification des employés sur la plateforme est traité àl’aide de trois programmes linéaires mixtes, résolus de façon séquentielle.La combinaison des deux modèles permet d’obtenir un modèle d’aide àla décision pour une plateforme de cross-docking. / In a cross-docking platform, goods are unloaded from inbound trucks,sorted and directly reloaded in outbound trucks – each product typicallystays less than 24 hours in the platform.By analyzing the gaps between the literature and on-field observations,we highlight two research directions: accounting for operational uncertainties,and for the human resource capacity in the platform.A truck scheduling problem with time windows for the inbound andoutbound trucks is modeled with an integer program and solved withthree different heuristics. The robustness of the schedules obtained is thentested with a discrete-event simulation model, which enables to evaluateseveral robust reformulations of the initial model.The employee timetabling and rostering problem in the platform is addressedwith three mixed integer linear problems solved sequentially. Thetwo models can be combined to serve as a decision-support tool for across-docking platform.

Dissertation (PhD)--Stellenbosch, 2004. / ENGLISH ABSTRACT: The dissertation reflects the research done on the design principles and success factors for the operation of cross dock facilities in grocery and retail supply chains. The cross dock is a particular facility in the supply chain where goods are received from suppliers, sorted without storage of the goods, and then efficiently moved to downstream customers. Cross docks are not a new operation. However, the use in high volume grocery and retail operational capabilities is poorly understood and is not uniquely defined. The problem is that cross docks are often seen as extensions of warehouses. The same personnel, systems and processes are applied and the efficiency potential of the cross dock is not achieved. Warehouses are orientated towards storing the full range of product and allowing the pick to be done from this storage buffer to provide any or all of these products to a customer. Cross docks will only handle products that are used in larger quantities and that are sent to most, if not all, the customers. The cross dock is therefore distinct and very different from the traditional warehouse. The published research tends to focus on the technical aspects of the cross dock layout. This research is primarily in the scheduling of the trucks into the yard of the facility; the allocation of trucks to specific doors of the facility; and the allocation of doors to receiving and despatch functions within the facility. Very little information or research reflects the design principles and success factors for the cross dock and its supply chain. The only classification of the cross dock in the literature is whether the barcode is added to the item before or after receipt at the cross dock. For this research work a literature survey was conducted and five major operations were reviewed, in South Africa and the USA. The research empirically drew logical conclusions, which were tested in the operations and found to be correct. This allowed the design principles and success factors to be determined for a successful cross dock. The research extends the knowledge of the cross dock operation and design: - • A new classification for the feasible types of cross docks in the supply chain was developed. Three factors are shown to be of primary importance: - o Where in the supply chain the identification of specific items for a customer is done; o Where the sort is done for the items to be delivered to a customer; and o Whether the supplier is providing one product or multiple products to the sort. From these three factors, eight potential classifications could be defined. However, only three practical types of cross dock can be determined from these eight alternatives. These are named in this research as Cross Dock Managed Load (CML); Joint Managed Load (JML); and the Supplier Managed Load (SML). The cross dock is far more effective than the warehouse when the total work (excluding inventory) is considered. The earlier in the supply chain the product is identified for the use of the entire downstream supply chain, the more effective will be the total supply chain. Thus the greatest supply chain effectiveness possible is with the SML, then the JML and finally the CML. • The operation of a cross dock is very similar to a continuous manufacturing process. There is no buffer of stock to decouple the inbound and outbound processes, and the operation takes place in a restricted area. However, in the retail chain, the workload alters with different orders and different days. Daily load differences vary by as much as 90%. This results in vastly different workloads and variations of throughput. This is similar to a batch operation with highly variable workloads between batches. The literature recommends the use of Just in Time (JIT) practice for cross docks. This is inappropriate as its primary requirements are continuous full volume operation and continuous small improvements to achieve a balanced operation. The most appropriate method of process improvement is the Theory of Constraints (TO C) and not JlT. • The management must have a detailed, disciplined approach. This implies standardised methods of operation, and a high degree of training. Equally there is the requirement for a special type of personnel to operate the cross dock. These operating personnel must be able to operate with precision (i.e. very low error rates) and be able to maintain this capability for continuous periods. • The systems required for a successful operation must include the capabilities of Yard Management, WMS for cross docking, Order Management with Advanced Shipping Notice (ASN) capability and Track and Trace across the supply chain. The items need to be identified by a barcode. The information required on the barcode will be determined by. the information systems capability of the least advanced service provider in the supply chain. If this service provider can receive and transmit all the data required for the supply chain from and to the other members, then the barcode need only be an identification number of the specific item. The data pertaining to the items is then passed from system to system in the supply chain. If data movement is not possible between all the parties in the entire supply chain, then the barcode must contain the information that will identify the item, the origin and the final delivery destination. If the items are delivered as part of a consignment, a further quantum of information is required to identify the total number of items in the consignment and the specific item within the consignment. • The research shows that the overall capability of the cross dock or its maximum capacity is the combination of the capability of the personnel and the cross dock design. Restrictions on either the personnel capability or the design of the cross dock, or both, severely reduces the effectiveness of the cross dock. • The previous research on the sequence of allocation of trucks to specific doors within the cross dock can be enhanced with a new sequencing method. The new method allocates the transport, in sequence of arrival, to the open door that either numrruses the walk distance in the facility; or maximises the completion of the consignments in order to minimise the area required to build the consignments; or a combination of both. The choice of these will be determined by the constraints imposed by the design of the building. This is an important extension as this ties the supply chain into the cross dock operation, rather than looking at the cross dock in isolation as has been done in this previous research. • The factors that influence the design of a cross dock as to its size, shape, number of doors, and the specifically required additional areas, is defined in detail. The principles of these factors and their inter-relationships and dependencies are used in a detailed design for a cross dock. The detailed design process is set out from data analysis through to the actual size calculations and layouts. Measurements of walk distance and sort movement are used to determine the most effective design. The design is shown to be considerably more effective than the older designs. This work has significantly extended the research on the design principles and success factors for implementation of cross docks in retail supply chains. The research derives a unique new classification for cross docks. An improvement is made to existing research on the allocation of the transport to particular doors in the cross dock. The operation, management and personnel are shown to require specific characteristics. The information systems required for effective cross docks is determined and defined. The identification of the individual items by barcode and the information required within the barcode depending on the information sophistication of the service providers in the supply chain is defined. A detail process to design a cross dock is evolved, with the full knowledge of the factors that must be considered and their interrelationships. Measurements to determine the effectiveness of the design are used to choose the most appropriate design. All these are then synthesised into a new design, which is far more effective than any of the other designs researched. The design process will produce a very effective cross dock as has been demonstrated with a new facility. / AFRIKAANSE OPSOMMING: geen opsomming

Cadeias de suprimentos podem ter operações seguindo diferentes estratégias de distribuição e a utilização de cada uma dessas estratégias pode resultar em diferentes operações e custos. A estratégia de cross-docking auxilia na redução dos custos de distribuição de produtos, consolidando cargas, e a redução de tempo e custos de armazenamento, uma vez que o tempo máximo de estoque permitido pela estratégia é de cerca de 24 horas. O objetivo deste trabalho é apresentar um modelo para o problema de cross-docking, em que cargas são entregues e reorganizadas de forma a atender a outras cargas que são coletadas e garantir que as janelas de tempo para início das operações sejam atendidas. Devido à falta de instâncias para o problema disponíveis na literatura, buscou-se gerar um benchmark e disponibilizá-las à comunidade científica. Uma vez que o problema é de difícil solução exata, um método heurístico para a resolução do problema foi desenvolvido. Os resultados mostraram que o modelo proposto resulta em boas soluções quando comparado ao modelo da literatura. O estudo de calibração do software IBM CPLEX mostrou que a calibração dos parâmetros pode resultar em melhores soluções e, por fim, a matheurística se mostrou competitiva com o CPLEX, principalmente para cenários em que a proporção de entregas e coletas diverge. / Supply chains may have operations which follow different distribution strategies and each one of these strategies may result in different operations and costs. The Cross-docking strategy helps to reduce the products distribution costs by consolidating loads and reducing storage costs as the maximum inventory time is approximately 24 hours. The aim of this research is to present a model for the cross-docking problem where loads are delivered and reorganized so as to cater for other loads that are collected and ensure that time windows are respected. Due to the lack of instances available in the literature, a benchmark was generated and was made available to the scientific community. As the problem is difficult to obtain the exact solution, a heuristic method was developed. The results showed that the proposed model has good solutions when compared to the literature model. A study of the IBM CPLEX software showed that tuning can result in better solutions and the matheuristcs was competitive with the software, mainly in scenarios where deliveries and pickups are very different.

Problem: Since there is not much inside information available, the problem that will be handled by this thesis is the coordination of warehousing activities within the logistics centers put to use by the Olympic Summer Games from 2000 to 2008. A special attention is given to certain requirements such as layout, capacity management, ownership and distribution applications. Purpose: The purpose of this thesis is based on warehouse requirementsand their specific adjustment to the Olympic Summer Games, further emphasizing on distribution applications influencing the capacityand ownership. Theory: The theoretical section touches upon event logistics, the Olympic Games and more importantly, logistics centers as a generic termfor distribution facilities and warehouses. Further, types of warehouses, capacity management, ownership and distribution applications are examined in order to be able to compare the various Games. Method: The method for this research is based on a case study conducted by semi-structured interviews with several people involved in the logistics organization of the Games. All interviews are conducted over the telephone and analyzed accordingly. However, secondary data was of high importance due to the limited number of interview respondents. Conclusion: All analyzed features of a warehouse facility had to be more efficiently and effectively performed in order to serve the great approach for the Olympic Summer Games. The implementation of distribution applications was not sophisticated enough to benefit capacity savings. The leased ownership situation and outsourcing to third party logistics providers were advantageous, but did not further influence the planning and utilization phase of the Olympic Games.