This paper evaluates how a firm uses vendor managed inventory (VMI) to manage inventories under costs constraint in uncertainly industrial environment and various demand. The emphasis of this research is to discuss the impacts how demand variation influences the effects of the firm executing VMI and how different supplier levels (ABC) affects firm¡¦s VMI strategy. This research built a cost model which contained construction cost, overhead cost, inventory cost, and shortage cost and compared the profits ex-using VMI with the profits using VMI. Furthermore, use the same model to find out the most proper VMI decisions in different supplier levels¡¦ conditions. This paper obtained some conclusions. First, the firm using VMI under uncertain demand would take more advantages than under certain demand. Second, we can find the best VMI strategy of a firm.

The screw nut (Fasteners) is known as the ¡§Rice of Industry¡¨. It is mainly applied on durable products such as automobile, electric apparatus, machinery, construction and building. Most of the durable products belong to the global products except the construction and building, which belong to regional. Due to the global competition, the competitions among the systems and supply chains have been formed. The improvement of the individual enterprise is not able to rely on the resource and ability of that organization only. It should operate across the border of the enterprises, and operate cooperatively with the downstream clients of the supply chains and the upstream manufacturers in order to improve the global competitiveness of the supply chain and seek for further development. Nowadays, the Vendor Managed Inventory (VMI) is the core of the trend of supply chain management (SCM) of global Fasteners industry. Taiwan is known as the empire of screw nut and it is not possible to neglect the operation trend of the global Fasteners market. This study attempts utilizing the characteristics of the System Dynamics, for which it is excellent on studying dynamic complicated system, to analyze the operation mechanism and structure of the Fasteners supply chain under VMI mode and applying synchronized mode. The individual dynamic model will be established to simulate the overall operation of the supply chain and compare the advantages and disadvantages of the two models. In addition, according to the major operation conditions and the demanding types, the model established by this study is utilized to develop the decision-making support tool for implementation of VMI mode of Fasteners industry. The conclusion of this study include (1) adding the synchronized model to Fasteners supply chain VMI mode can improve the operation performance of the enterprise, (2) to establish the design principle and steps of adding the design of synchronization to VMI mode. There are two contributions in this study: (1) the collocation of adding synchronization to the VMI mode model has proved that the combination with the synchronization mode can improve the performance of VMI mode. (2) The design principle and steps of adding the design of synchronization to VMI mode can be the reference for design steps of adding synchronization mode to the industry that implements VMI operation mode.

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<p>Med större krav på effektivisering och pressade kostnader har VMI på senare tid blivit en allt mer tillämpad metod för att samordna aktiviteterna i försörjningskedjan. Mycket forskning har gjorts kring ämnet VMI och dess fördelar. Däremot har inte mycket skrivits om initiativtagande och hur dessa samarbeten uppstår.</p><p>Syftet med uppsatsen är att undersöka företag som tillämpar VMI. Detta för att ta reda på vem, kunden eller leverantören, som tar initiativet till samarbetet och varför. Utifrån detta vill vi även identifiera konsekvenser kopplade till vem som tog initiativet.</p><p>Genom vår undersökning har vi kommit fram till att kunden så väl som leverantören kan vara initiativtagare. Detta för att det finns vinster att göras för båda parter. Vi har kunnat identifiera att den främsta anledningen till initiativtagande är de fördelar som ses för det egna företaget. En annan bidragande faktor är även att företagen vill skapa långsiktiga relationer. Vi har genom vår studie inte kunnat identifiera några konsekvenser i samarbetet som är direkt kopplade till vem som tar initiativet. Däremot har vi sett indikationer på att den part som tar initiativet är den som ofta bäst lyckas påverka villkoren för samarbetet.</p>

Abstract Today, the market is getting tougher and tougher and organisations need to concentrate more on the organisations core competence, to become successful and gain competitive advantage. One way to get this competitive advantage for an organisation is to start using Vendor Managed Inventory (VMI) system. A VMI system, with the help of Electronic Data Interchange (EDI), manages the informational and material flow between the distributor and the supplier by automation. This means that the supplier receives accurate information from the distributor, and can thereby plan deliveries of products when needed and at the right amount. These deliveries are done by automation and are based on the distributor’s shared information such as inventory- and sales figures. We have as a goal for this thesis to examine if the positive benefits described by literature do reflect those benefits with the benefits experienced by organisations. The following question will be discussed and answered during this thesis: • Do the benefits of a VMI system described in theories, match the benefits experienced by an organisation? To answer our question, we have interviewed two managers about their companies’ way to use VMI. One interview was performed at a store working in the retail market and the other interview was performed at a grocery store. The interviews were performed to receive a deeper understanding of what the managers think about VMI, and also to understand how these benefits have been beneficial for their company. After the interviews, we started to compare and analyse the benefits gathered from literature with the benefits experienced by the managers for the companies. The analysis and comparison proved that there is a similarity between the benefits gathered from literature and the benefits experienced by the interviewees. We decided to categorise the benefits into three different categories: costs, service and inventory. Believing that this categorization was a good way to get you as a reader to have a lucid overview of which the benefits are, and which area of business they are beneficial in. Many of the gathered benefits could affect more than one area of business, and many cases benefits are created through chain reactions, benefits breeds new benefits. The similarity of the benefits collected from the empirical findings compared with the benefits from theories, are striking, and we can thereby concluded that the experienced benefits by an organization using a VMI system highly represents the benefits described in the theories from literature. / I dagens hårda verklighet så måste varje organisation koncentrera sig mer och mer på sin kärnkompetens, om det ska vara med ute och slåss på den allt hårdare marknaden. Ett sätt att göra detta är att börja använda sig av ett Vendor Managed Inventory (VMI) system. Ett VMI system med hjälp av Electronic Data Interchange (EDI) styr informations- och materialflödet mellan organisationen och dess leverantörer automatiskt. Detta betyder att leverantören får rätt information om sin kunds behov, och kan därmed planera tids- och kvantitetskorrekta leveranser till sin kund. Denna leverans görs automatiskt genom informationsdelningen så som lager nivåer, försäljningssiffror osv. överförs från distributören till leverantören. Vi har i denna kandidatuppsats koncentrerat oss på att undersöka om de positiva fördelarna som står i litteratur verkligen stämmer överens med upplevda fördelar som olika organisationer har uppmärksammat vid användningen av VMI. Frågan som styrt denna uppsats är följande; • Stämmer de fördelar som står i litteraturen överens med de upplevda fördelar som organisationer har märkt? För att få svar på vår fråga har vi använt oss av att intervjua två butikschefer om sina respektive företag. En intervju utfördes på en affär inom detaljhandeln och den andra utfördes i en matvarubutik Intervjuerna användes för att få en djupare förståelse om vad de intervjuade tyckte om användandet av VMI, samt för att försöka förstå hur fördelarna av VMI har varit till fördel för deras företag. Efter att ha analyserat och jämfört de fördelar som vi fann i litteraturen med de upplevda fördelar funna hos de intervjuade organisationerna analyserade vi dem. Analysen visade att de fördelar som finns i litteraturen överensstämde med de upplevda fördelar som organisationerna har uppmärksammat. Vi kategoriserade fördelarna i tre skilda kategorier; kostnader, service och lager. Detta gjordes i tron på att det skulle underlätta för läsarna att lättare kunna skapa sig en överblick över vilka fördelar som fanns och för vilka område dessa fördelat påverkar. Många av de funna fördelarna kan dock påverka mer än ett område, det kan också skapas kedjereaktioner på vissa fördelar, fördelar föder nya fördelar. Likheterna mellan de insamlade fördelarna från litteraturen jämfört med de insamlade fördelarna från intervjuerna är slående, vi kan härmed säkerställa att de upplevda fördelarna från intervjuerna mycket väl överensstämmer med de fördelar som vi fann i litteraturen.

Examensarbetet om 15 högskolepoäng omfattar området gruvutrustning på avdelningen strategiskt inköp på Atlas Copco. Bakgrunden till arbetet är att Atlas Copco ständigt strävar efter att minska produktionskostnaden i monteringen utan att påverka kvaliteten, ett viktigtarbete i detta är att säkerställa ett jämnt materialflöde. Atlas Copco är ett världsledande teknikföretag som utvecklar och tillverkar innovativa kompressorer, vakuumlösningar och luftbehandlingssystem, anläggnings- och gruvutrustning, industriverktyg och monteringsystem. Avdelningen strategiskt inköp ansvarar för att teckna kommersiella avtal med leverantörer som producerar artiklar till monteringsarbetet i produktionen. Examensarbetet definieras som en materialflödesanalys som berör materialhantering av direkt material till Atlas Copcos montering. Vidare avgränsades arbetet mot det interna VMI (Vendor Managed Inventory) konfigurerade konsignationslagret. Centralt för projektet har varit att med en grundlig teoretisk analys fastställa de styrande parametrarna som detta lagerkoncept bör använda sig av. Arbetet har resulterat i att rekommendationer har tagits fram till företaget. / The thesis of 15 credits includes the mining equipment on strategic purchasing department at Atlas Copco. The background on the project is based on that Atlas Copco constantly strives to reduce product cost in the assembly process without affecting quality, and important job in this is to ensure a steady flow of material. Atlas Copco is a world leading technology company that develops and manufactures innovative compressors, vacuum solutions, air treatment systems, constructions- and mining equipment, industrial tools and assembly systems. The strategic purchasing department is responsible for signing commercial agreements with suppliers that produce items for assembly work in the production. The thesis is defined as a material flow analysis involving material handling of direct materials to Atlas Copcos assembly. Later on the project was defined to the internal VMI (Vendor Managed Inventory) configured consignment stock. The main goal in the project was to, through a thorough theoretical analysis, be able to determinate the leading parameters that should be used by this stock type. The work has resulted in recommendations to the company.

Cette thèse présente la dynamique ultrarapide de relaxation de molécules photochromes et des agrégats d'argon en phase gazeuse à l'échelle femtoseconde. Des expériences utilisant la technique « pompe-sonde » ont été menées sur un dispositif utilisant un faisceau moléculaire pulsé couplé à de l'imagerie de vitesse de photoélectron/photoion (VMI) et un spectromètre de masse à temps de vol (TOF-MS). Ces études nous ont permis de caractériser les changements de distribution électronique des différents systèmes en fonction du temps. Par ailleurs une étude théorie/expérience sur la caractérisation de la densité et de la distribution de vitesse au sein d'un faisceau moléculaire pulsé a aussi été réalisée. Dans le cas de la dynamique des dithienyléthènes, nous avons observé des mécanismes de relaxation électronique parallèles. Le paquet d'onde initial se sépare en deux parties distinctes. Une première partie se dirige vers l'état fondamental via une intersection conique, tandis que la deuxième partie reste quelques picosecondes dans l'état excité en oscillant avant de relaxer vers l'état fondamental. Cette étude nous a permis de comprendre la dynamique intrinsèque des différentes molécules étudiées, mais aussi d'étendre le mécanisme de relaxation à toute cette famille de molécules photochromes dans les trois phases dans lesquelles elles sont étudiées. Dans le cas des agrégats d'argon, deux phénomènes ont été observés à différentes échelles de temps. Le premier se produit dans les premières picosecondes et est la relaxation électronique d'un état excitonique à une vitesse d'environ 1 eV.ps⁻¹. Le deuxième phénomène résulte de la localisation de l'excitation sur une paire Ar₂* que nous avons pu observer à partir de 4-5 ps. L'éjection d'atomes d'argon excités a aussi été observée, nous permettant ainsi de connaitre la durée de vie maximale de l'état excitonique délocalisé. Ce travail a permis d'apporter des informations supplémentaires à celles fournies par les études réalisées en phase condensée. Il ouvre donc la voie vers l'étude de systèmes plus complexes tels que les nanoparticules en phase gazeuse. / This PhD thesis investigated the ultrafast dynamics of photochromic molecules and argon clusters in the gas phase at the femtosecond timescale. Pump-probe experiments are performed in a set-up which associates a versatile pulsed molecular beam coupled to a photoelectron/photoion velocity map imager (VMI) and a time-of-flight mass spectrometer (TOF-MS). Theses pump-probe experiments provides the temporal evolution of the electronic distribution for each system of interest. Besides, a modelization has been performed in order to characterize the density and the velocity distribution in the pulsed beam. Regarding the photochromic dithienylethene molecules, parallel electronic relaxation pathways were observed. This contrasts with the observation of sequential relaxation processes in most molecules studied so far. In the present case, the initial wavepacket splits in two parts. One part is driven to the ground state at the femtosecond time scale through a conical intersection, and the second part remains for ps in the excited state and experiences oscillations in a suspended well. This study has shed light into the intrinsic dynamics of the molecules under study and a general relaxation mechanism has been proposed, which applies to the whole family of dithienylethene molecules whatever the state of matter (gas phase or solution) in which they have been investigated. Concerning argon clusters excited at about 14 eV, two behaviors of different time scale have been observed at different time scales. The first one occurs in the first picoseconds of the dynamics. It corresponds to the electronic relaxation of an excitonic state at a rate of 1 eV.ps⁻¹. The second phenomenon corresponds to the localization of the exciton on the excimer Ar₂*. This phenomenon is observed 4-5 ps after the excitation. In this study, we also observed the ejection of excited argon atoms, addressing the lifetime of the delocalized excitonic state. This work provide additional informations compared to those contributed in condensed phase and it pave the way for new studies in gas phase on more complex system such as nanoparicles.

Made available in DSpace on 2015-04-22T22:10:22Z (GMT). No. of bitstreams: 1 Helido Guedes Montenegro Filho.pdf: 2333644 bytes, checksum: 3a009dbcac0a54d285c882e1a0f92df4 (MD5) Previous issue date: 2011-06-02 / O presente trabalho é um estudo de caso no qual foi analisado um processo adotado por uma empresa no Polo Industrial de Manaus. O novo processo foi adotado em decorrência de circunstâncias especiais ocorridas junto aos fornecedores que possuem empresas no município de Manaus, e que ora realizam entregas de matérias-primas para a empresa. Foi implantado um processo que elimina a necessidade de comunicação baseado em dados manuais com os fornecedores, promovendo sincronia com a execução das linhas de manufatura, denominado de entrega direta à linha de produção (EDLP). Esta ferramenta habilitou o fornecedor entregar apenas certa quantidade de estoque necessário as ordens de produção, no momento correto da execução na linha de manufatura, evitando assim estoques desnecessários no armazém da empresa. Os fornecedores recebem os pedidos em ciclos de quatro horas, procedendo assim com suas entregas, na certeza que serão prontamente recebidos, sendo suas peças endereçadas diretamente às linhas de manufatura, para conclusão e adequação aos requisitos dos clientes finais da empresa. O método utilizado para estudar a aplicação do conceito do processo de entrega direta à linha de manufatura foi o Estudo de Caso, pois possibilitou a observação de uma realidade através de um método científico, havendo a necessidade de observar aspectos que validam o processo investigativo como, por exemplo, a confecção de um protocolo de pesquisa. Foi necessário elaborar um referencial teórico da literatura disponível sobre assuntos tais como; a Manufatura Enxuta e o uso de JIT e Kanban, a Produção Sincronizada e o uso do MRP e MRP II e no Suprimento Automático o uso de CRP e VMI. Ainda foi necessário elaborar uma pesquisa bibliográfica em assuntos como a utilização de ferramentas de tecnologia de informação (TI) na cadeia de suprimento, processos colaborativos de suprimento entre os quais se destaca o DSD (Direct Store Delivery). Os dados primários foram coletados através de aplicação de questionários individuais sobre o processo junto ao envolvidos de forma habilitar a comparação entre a teoria analisada e os fatos observados pelo público alvo da investigação. Os dados secundários foram levantados através dos procedimentos e instruções de trabalho referentes ao processo de entrega direta à linha de produção, provendo embasamento documental à pesquisa. Foram ainda analisados fluxos e mapas de processo sempre que disponíveis para consulta, tanto na empresa como nos fornecedores que atuam como parceiros. Portanto, baseado nos indícios levantados observou-se a validade das proposições retiradas da teoria. Após a análise do processo de entrega direta à linha de produção, compreende-se que este processo pode colaborar com a redução dos estoques de processo nas empresas através da promoção de um processo alinhado entre a forma como será executado o plano de produção, e a forma como os fornecedores são acionados e devem responder este chamado. Estes aspectos aliados a tecnologia da informação e um processo controlado de execução sincronizada favorecem o processo de entrega direta à linha de produção, levando a empresa a concluir que não há necessidade de manutenção de estoques intermediários desnecessários ao processo de produção realizado nas linhas de produção da empresa.

No presente trabalho é proposto um modelo de simulação de uma cadeia de suprimentos integrada com adoção da estratégia de VMI (Vendor Managed Inventory) entre uma empresa do setor de minério de ferro e alguns de seus fornecedores estratégicos. O modelo baseia-se em uma estrutura de avaliação de sistemas VMI adaptada de Sarpola et al. (2007) em conjunto com as configurações de cadeias de suprimentos propostas por Holmström et al (2003), o que permite medir o desempenho da cadeia de suprimentos segundo 3 níveis de integração. É feita uma revisão bibliográfica dos conceitos da estratégia de VMI, políticas de estoque em sistemas integrados, compartilhamento e grau de visibilidade de informações ao longo da cadeia de suprimentos. Os resultados obtidos possibilitam realizar uma análise quantitativa dos benefícios do VMI, onde são considerados demanda estocástica, lead time aleatório, produtos com características diferentes, compartilhamento de informações, visibilidade parcial da cadeia de suprimentos, lotes variáveis, cálculo dos estoques de segurança considerando informações dos pedidos, demanda real do cliente e erros de previsão. / In this paper we proposed a simulation model of an integrated supply chain with the adoption of VMI (Vendor Managed Inventory) strategy between a company of the iron ore and some of its strategic suppliers. The model is based on a framework for evaluating VMI systems adapted from Sarpola et al. (2007) together with the configurations of supply chains proposed by Holmström et al (2003), which measures the performance of the supply chain using 3 levels of integration. It is a literature review of the concepts of the strategy of VMI, inventory policies in integrated systems, sharing and degree of visibility of information throughout the supply chain. The results allowed to perform a quantitative analysis of the benefits of VMI, which are considered as stochastic demand, random lead time, products with different characteristics, information sharing, partial visibility of the supply chain, lots of variables, calculation of safety stocks based on information from client orders, actual customer demand and forecasting errors.

O foco dessa dissertação está na gestão de estoques em sistemas multicamadas. O modelo de simulação construído considera o desempenho histórico de uma cadeia de distribuição de medicamentos versus a política de gestão proposta. Os objetivos principais do trabalho são: a avaliação quantitativa da política de cálculo de necessidades aplicada na gestão de sistemas multicamadas, a verificação da importância da cooperação entre os elos da cadeia de distribuição para gestão do fluxo de materiais e o estudo das curvas que representam o dilema ‘nível de serviço’ versus ‘custo total da cadeia’. O modelo considera o fluxo de materiais a partir do estoque em processo do laboratório até a venda para as farmácias, que pode ser aproximada pela demanda dos medicamentos visto que os estoques das farmácias são relativamente pequenos e constantes ao longo do tempo. A modelagem de custos leva em conta o custo de estoque do laboratório e dos distribuidores, o custo de pedido dos distribuidores, o custo de transporte, o custo de entrega com atraso do laboratório e o custo de venda perdida dos distribuidores. Especificamente, são considerados cenários com e sem o compartilhamento de informações entre as empresas da cadeia. Consideram-se também cenários com e sem sazonalidade na demanda. Inicialmente, cada cenário simulado é preparado com a definição do ‘período transitório da simulação’, ‘horizonte de simulação’ e ‘número de réplicas’ necessárias. Depois disso, é feito o delineamento de experimentos para identificar quais variáveis de decisão têm efeito significativo sobre o custo total da cadeia. Finalmente, é feita uma busca da parametrização de cada um dos cenários que apresente o melhor custo total da cadeia. Os resultados da simulação mostraram que as práticas atualmente empregadas na gestão dos estoques das empresas podem ter seu desempenho melhorado com a utilização da política simulada na pesquisa. Os cenários nos quais se considerou o compartilhamento de informações tiveram desempenhos semelhantes aos sem esse compartilhamento. Dessa forma, para a política simulada, conclui-se que o valor do compartilhamento de informações foi relativamente pequeno. Nas simulações pode-se verificar a melhoria simultânea do nível de serviço e do nível de estoques da cadeia. Isso mostra que a política simulada mudou o dilema (trade-off) que interliga antagonicamente essas duas características de desempenho do sistema. / This dissertation focuses on the inventory management for multi-echelon systems. The simulation model proposes a new inventory management policy and compares it to the historical performance of a medicine supply chain. The main objectives of this research are: the quantitative analysis of the method used for the calculation of material requirements in multi-echelon systems; the verification of the importance of the cooperation between the components of the supply chain to the material flow management; and the analysis of the curves which represent the trade-off between ‘service level’ and ‘total cost’. The model takes into account the material flow from the laboratory’s ‘work in process’ up to the sales to the drugstores, which can be approximated by the demand of the final consumer, since the inventory kept by drugstores is relatively small and constant in time. The costs are calculated considering: the laboratory’s and distributors’ inventory costs, the cost of orders from the distributors, the transportation cost, the laboratory’s cost of late delivery and the distributors’ cost of lost sales. Scenarios with and without the sharing of information between the components of the supply chain were both considered. The same is true for scenarios with and without seasonality in the demand. Initially, each scenario was prepared with the definition of the ‘warm-up’ period, the simulation horizon and the amount of required replications. Secondly, the design of experiments (DOE) was done in order to determine which decision variables have influence on the supply chain total cost. Finally, each scenario was tested with many different parameters in order to find the lowest cost for the supply chain. The simulation results have showed that the procedures currently applied for the inventory management can have their performance improved by the use of the policy proposed in this research. The results for the scenarios with the sharing of information were similar to the ones for the scenarios without the sharing. For that reason, we can conclude that, for the proposed inventory management policy, the value of the sharing of information through the supply chain was relatively small. In the simulations, both the ‘service level’ and the ‘total cost’ have improved. In this manner, it can be said that the new policy has improved this trade-off.