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.

Adapting from System Dynamics methodology for model building and simulation, this paper provides a structural and systematic approach toward analyzing the actual operations of Vendor Managed Inventory in fastener supply chain and constructs application steps for implementation. Optimum replenishment parameters of VMI model are established through scenario designs, dynamic simulations, parameters tuning and key performance index measuring. Four key findings are: (1) VMI model is able to reinvent the competitive advantage of an enterprise and enhance the competitiveness of the entire industry; (2) the key success factor of VMI is acquisition and integration of the dynamic information over the supply chain; (3) the efficiency and effectiveness of VMI operation can be enhanced through dynamic modeling and parameter tuning; (4) Systematic modeling approach provide feasible methodology in solving real world VMI problems.

The Global Supply Chain Forum (Stanford Global Supply Chain Forum Web Resource, http://www.stanford.edu/groups/scforum) defines supply chain management (SCM) as “Supply chain management is the integration of key business processes from end user through original suppliers that provides products, services and information that add value for customer and other stakeholders.” The rapid development of the Internet has dramatically changed the traditional definitions of manufacturer, suppliers and customers. Newer approaches to supply chain management attempt to organize the supply chain as a network of cooperating intelligent agents, each performing one or more supply chain functions and each coordinating actions with one another. This research is aimed at creating a viable model of a single manufacturer single supplier collaborative supply chain system using a Vendor Managed Inventory (VMI) system. The research further uses known inventory performance parameters to performance benchmark the VMI system with traditional push-pull systems, develop a collaborative forecasting spreadsheet solution and a best alternative ordering policy amongst EOQ, Monthly, JIT and VMI policies under known lead time and a variety of demand distribution functions. / Master of Science

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.

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.

[pt] O foco deste estudo está na avaliação da indústria farmacêutica brasileira sob o ponto de vista de suas operações de logística e as relações entre as empresas que compõem sua cadeia de distribuição. Os objetivos principais desta dissertação são entender a dinâmica do setor farmacêutico nacional, desde a consolidação de suas operações em nível mundial e seus reflexos no Brasil, até as atuais tendências gerenciais no sentido de otimizar processos produtivos. A partir deste cenário competitivo estudar-se-ão técnicas modernas de gestão da cadeia de distribuição que visam um desempenho superior, possibilitando vantagens aos seus participantes. Em particular serão abordadas técnicas de reposição automática de estoques e o seu atual estágio de aplicação na indústria farmacêutica brasileira. Busca-se compreender, além disso, como as operações logísticas podem trazer benefícios a uma atividade sensível à saúde da população, bem como de que forma as empresas brasileiras estão se preparando para adotar novos sistemas de gestão de cadeias de suprimentos se é que elas estão. / [en] The focus of this study is to evaluate the Brazilian pharmaceutical industry under the perspective of its logistics operations, and the relations between the companies that work together in a distribution chain. The main goal of this dissertation is to understand the dynamics of the domestic pharmaceutical sector, since the consolidation of its global operations and their consequences in Brazil. To reach this objective there will be analyzed the most recent managerial tendencies towards the optimization of the manufacturing processes from raw materials to finished goods. In this competitive scenario there will be studied the new techniques of supply chain management that aim a superior performance. In particular, there will be reviewed systems of inventory automatic replenishment and its present stage of development in Brazilian pharmaceutical industry. Finally, we will try to understand how logistics operations can benefit such a sensitive activity to people s health, as well as how Brazilian companies are getting ready to adopt new systems of supply chain management - if they are.

<p>Till följd av marknadens utveckling har beroendet av informationsutbyte och samverkan i olika nätverk ökat. De senaste årtiondenas fokus på informationsutbyte och samarbete ledde till att Supply Chain Management uppstod. Flera forskare har karakteriserat lyckad styrning av samverkan som en kärnkompetens som krävs för att vara konkurrenskraftig. Ägande och kontrollfunktioner som tidigare låg inom samma verksamhet har förändrats och tillämpningen av VMI har uppkommit. VMI innebär att leverantören övertar ansvaret för lagerstyrningen hos kunden. Samarbetet kräver effektivt informationsflöde inom försörjningskedjan och ett bättre informationssystem, vilket ökar möjligheten att förbättra kedjans effektivitet. Vi hade, med den här utgångspunkten i åtanke, för avsikt att besvara problemformuleringen: Hur hanteras information i VMI-styrda relationer inom koncerner? Syften med undersökningen var att undersöka hur lagerstyrning i form av VMI fungerar i en koncern, förklara hur VMI påverkar informationsflöde och relationer i en koncern samt att analysera betydelsen av VMI för informationsutbytet. Efter teoretiska studier genomfördes en undersökning på en koncern där VMI har införts och givit resultat. Resultaten från intervjuerna har sedan analyserats och vi har kommit fram till följande. För att hantera information i VMI-styrda relationer krävs att det finns bra system, en tydlig ansvarsfördelning och förtroende mellan parterna.</p>

Till följd av marknadens utveckling har beroendet av informationsutbyte och samverkan i olika nätverk ökat. De senaste årtiondenas fokus på informationsutbyte och samarbete ledde till att Supply Chain Management uppstod. Flera forskare har karakteriserat lyckad styrning av samverkan som en kärnkompetens som krävs för att vara konkurrenskraftig. Ägande och kontrollfunktioner som tidigare låg inom samma verksamhet har förändrats och tillämpningen av VMI har uppkommit. VMI innebär att leverantören övertar ansvaret för lagerstyrningen hos kunden. Samarbetet kräver effektivt informationsflöde inom försörjningskedjan och ett bättre informationssystem, vilket ökar möjligheten att förbättra kedjans effektivitet. Vi hade, med den här utgångspunkten i åtanke, för avsikt att besvara problemformuleringen: Hur hanteras information i VMI-styrda relationer inom koncerner? Syften med undersökningen var att undersöka hur lagerstyrning i form av VMI fungerar i en koncern, förklara hur VMI påverkar informationsflöde och relationer i en koncern samt att analysera betydelsen av VMI för informationsutbytet. Efter teoretiska studier genomfördes en undersökning på en koncern där VMI har införts och givit resultat. Resultaten från intervjuerna har sedan analyserats och vi har kommit fram till följande. För att hantera information i VMI-styrda relationer krävs att det finns bra system, en tydlig ansvarsfördelning och förtroende mellan parterna.

Abstract Kongsberg Automotive (KA), a first- and second-tier supplier to some of the largest automotive manufactures, has acknowledged the need to enhance their competitiveness and to collaborate within the supply chain. In order to do this, KA must improve the current business processes by establishing long term relationships with their suppliers. Today, KA face a high level of inventory, which has resulted substantial amount of tied up capital and inefficient processes. Therefore, this study will evaluate KA’s and three chosen suppliers’ possibilities and the effects that a vendor managed inventory (VMI) partnership will imply. VMI is a concept within supply chain management, where the supplier is fully responsible for managing the customer’s inventory level. To achieve this, the supplier is given access to sensitive information of the customer’s inventory level and demand and can, thereby, replenish the customer’s stock when needed. Although, some firms have embraced the concept with success, others have retreated forcefully. To fulfil the purpose of this study, we have done a broad literature review regarding VMI and performance measurements, as well as, organisational structures and information sharing in collaborative partnerships. Further, to better understand the implementation and effects of VMI, a benchmarking study was made at Volvo Powertrain in Skövde, an early VMI pioneer. In addition to the thorough study of KA’s processes, field visits were made at the suppliers’ to visualize their material and information flow in order to examine in what areas VMI would have an impact. The conclusion of this study is that a VMI strategy, in supplement with a consignment stock policy, is possible for KA. However, issues concerning responsibilities and ownership have become apparent throughout the study that needs to be agreed upon. Further, the study indicates that the benefits from a VMI implementation will be greater for KA, than for the suppliers. Specifically, a reduction in inventory value can be attained by KA, while the suppliers only can obtain minor improvements within the areas of inventory, production, and order processing. On the other hand, the suppliers will face drawbacks, mainly in their order processing, which will result in increased costs. However, we advice KA to further discuss and test the VMI and consignment stock strategy in a pilot project in order to find the right solution for the company and the suppliers.

Vendor Managed Inventory (VMI), Consignment Inventory (CI) and a combination of both (C&VMI) are supply-chain sourcing agreements between a vendor and customer. VMI allows the vendor to initiate orders on behalf of the customer. In CI, the customer pays for the goods supplied by the vendor only upon use. The vendor under C&VMI decides customer-replenishments, and owns the goods replenished until they are deployed by the customer. Our thesis studies these agreements in three essays. <br /><br /> The first essay considers a vendor <em>V</em> that manufactures a particular product at a unique location. That item is sold to a single retailer, the customer <em>C</em>. Three cases are treated in detail: Independent decision making (no agreement between the parties); VMI, whereby the supplier <em>V</em> initiates orders on behalf of <em>C</em>; and Central decision making (both Vendor and Customer are controlled by the same corporate entity). <br /><br /> Values of some cost parameters may vary between the three cases, and each case may cause a different actor to be responsible for particular expenses. Under a constant demand rate, optimal solutions are obtained analytically for the customer's order quantity, the vendor's production quantity, hence the parties' individual and total costs in the three cases. Inequalities are obtained to delineate those situations in which VMI is beneficial. <br /><br /> The problem setting in the second essay is the same with that of Essay 1, but the sourcing agreements investigated are now CI and C&VMI. In CI, as in the usual independent-sourcing approach, the customer has authority over the timing and quantity of replenishments. CI seems to favour the customer because, in addition, he pays for the goods only upon use. Under a C&VMI agreement, the vendor still owns the goods at the customer's premises, but at least can determine how much to store there. <br /><br /> The second essay thus contrasts the cases CI and C&VMI, and compares each of them to a no-agreement case. General conditions under which those cases create benefits for the vendor, the customer and the whole chain are determined. <br /><br /> Essay 3 investigates VMI and C&VMI separately for a vendor and multiple customers who face time-varying, but deterministic demand for a single product. In any of those agreements, the vendor seeks the best set of customers to achieve economies of scale. MIP models are developed to find that set of customers, and to determine the vendor's optimal production, transportation, and customer-replenishment quantities. The model for VMI is solved using a heuristic that produces two sub-models, and uses hierarchical solution approach for production, customer-replenishment and transportation decisions. C&VMI model is solved using Lagrangian relaxation. Various numerical examples are used to test the solution approaches used. <br /><br /> In the mean time, the customers can guarantee to be no worse off under VMI or C&VMI than the no-agreement case by setting the right levels of maximum inventory. A model to determine those levels and a solution algorithm are also proposed in Essay 3. <br /><br /> The first two essays can help a vendor or customer in a supply chain to determine the least costly sourcing option, which depends on the relative values of various cost parameters. A vendor with multiple customers can make use of the results in the third essay, which reveal the best possible economies of scale under VMI or C&VMI. Those customers can guarantee to be no worse of than traditional sourcing when they set the proposed levels of maximum inventory.