O ambiente competitivo atual tem colocado pressão no processo de tomada de decisão no mundo corporativo. Os trade-offs das prioridades competitivas discutidos na elaboração da estratégia como custo, qualidade, serviço e flexibilidade já não são suficientes. Estes trade-offs, embora importantes no curto prazo, devem ser compatibilizados de modo que as empresas que tenham o melhor balanço entre eles devam ter resultado superior. Um dos trade-offs bastante discutido é o equilíbrio entre serviço e estoque. A percepção é que seja improvável alcançar excelência no serviço sem ter um considerável nível de estoque. Deste cenário nasce então o paradoxo do uso de sistemas MRP (Material Requirement Planning) versus sistemas JIT (Just in Time), ou melhor, sistemas empurrados versus puxados, já que a escolha por um ou outro sistema tem ligação íntima com a gestão de estoque. Se por um lado os sistemas MRP são largamente utilizados, via softwares ERP, por outro sistemas JIT têm trazido importantes melhorias nos resultados. Embora muitas empresas considerem a adoção exclusiva de um ou outro sistema, algumas delas têm adotado um processo híbrido com o objetivo de tirar o melhor de cada sistema e gerar assim desempenho superior. O objetivo deste trabalho é investigar como as empresas inseridas em mercados caracterizados pela concentração de demanda no final do mês (fenômeno conhecido como hockey-stick), e baixo acerto nas previsões de demanda, estão aplicando suas estratégias de planejamento de produção e seus ERP. Se por um lado a baixa acurácia nas previsões causa um problema na aplicação de estratégias empurradas de planejamento, pois requer um alto estoque de segurança associado, por outro a concentração de embarque dificulta a adoção de uma estratégia puramente puxada, já que o sistema não tem a estabilidade necessária. Para cumprir com este objetivo seis estudos de caso foram conduzidos e os resultados encontrados, suportados pela teoria, sugerem o aparecimento de um modelo híbrido eficaz para planejamento no ambiente estudado assim como o aparecimento de um sistema DSS (Decision Support System). Outra contribuição desta pesquisa foi identificar, em um dos casos, uma empresa que conseguiu atacar de maneira eficaz o fenômeno em sua causa raiz neutralizando assim seus efeitos. / The highly competitive environment of modern times has put pressure on the decision-making process in the corporate world. The trade-offs of competitive priorities such as cost, quality, service and flexibility are no longer enough. These trade-offs, albeit important in the short term, must be matched so that companies that have the best balance between them should have superior results. One of the tradeoffs widely discussed is the balance between service level and inventory. The perception is that excellence is not likely to be achieved in service without having a significant level of inventory. From this scenario comes the paradox of using MRP systems (Material Requirement Planning) versus JIT systems (Just in Time), or rather \"pushed\" systems versus \"pulled\" systems since the option for one or the other system has a close connection with inventory management. On the one hand, MRP systems are widely used in industry through ERP software; on the other hand, JIT systems have obtained better results. While many companies consider adopting one or another system, some of them adopt a hybrid process with the goal of taking the best of each system and generate superior performance. The purpose of this research is to investigate how companies inserted in markets characterized by sales peak at the end of the month (hockey-stick phenomenon), and low accuracy in demand forecasts, are applying their production planning strategies and their ERP. Low forecast accuracy causes a problem in applying pushed strategies as it requires a high safety stock associated. Conversely, the sales peak hinders the adoption of a purely pull strategy since the system does not have the necessary stability. To meet this goal, six case studies were conducted and the results found and supported by the theory suggest the emergence of an effective hybrid model for planning in the environment studied as well as the appearance of a DSS (Decision Support System). Another contribution of this research was to identify in one of the cases a company that managed to effectively tackle the phenomenon in the root cause, neutralizing its effects.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-05-20T13:25:28Z No. of bitstreams: 1 2014 - Timoteo Andre Stuker.pdf: 2292716 bytes, checksum: 2f422b087fcce44075984f39efd5f016 (MD5) / Made available in DSpace on 2015-05-20T13:25:28Z (GMT). No. of bitstreams: 1 2014 - Timoteo Andre Stuker.pdf: 2292716 bytes, checksum: 2f422b087fcce44075984f39efd5f016 (MD5) Previous issue date: 2014-09-12 / Nenhuma / Para produtos de moda, a demanda é de difícil previsão por modelos lineares ou polinomiais e o ciclo de vida dos produtos é curto. Os varejistas são obrigados a tomarem as decisões de sortimento de produtos e quantidades de compra e estoques bem antes da época da venda, quando apenas informações limitadas e imprecisas estão disponíveis. As decisões são tomadas basicamente confiando em dados qualitativos e questões subjetivas. Os erros na previsão da demanda associados a esse modelo de tomada de decisão se aproxima de 50%. No entanto, as previsões de demanda podem ser melhoradas atualizando as previsões com base nas vendas iniciais. Nesse contexto, o objetivo do presente trabalho é propor um modelo de previsão de demanda baseado no aprendizado com as vendas iniciais para uma cadeia de suprimentos de um varejista de calçados. O modelo foi aplicado em uma rede de varejo calçadista brasileira, na coleção de Verão 2013/2014. O modelo de previsão de demanda foi proposto em duas etapas: (i) a primeira que utilizou dados históricos de vendas agregados por subgrupo de produtos, por loja; e (ii) a segunda que utilizou dados das vendas iniciais para desagregar a previsão por subgrupo na previsão por produtos e cores. Para gerar a previsão de longo prazo foi utilizado o modelo logístico. A Razão de Incremento Semanal (RIS), que é a previsão de vendas semanal por subgrupo dividida pela quantidade de produtos vendidos, foi utilizada como dados de entrada para decompor a previsão em produtos e cores. Além dessa informação, são entradas a quantidade vendida na primeira semana e a quantidade de produtos em estoque. A partir da modificação do cálculo da cobertura de estoques para incluir o RIS, tem-se a previsão de demanda atualizada. A previsão também considera a demanda de substituição e a quebra de grade. Os resultados encontrados demonstraram que o modelo de previsão de demanda atualizado com os dados de vendas obteve desempenho superior ao modelo de previsão original. O modelo de previsão de longo prazo se mostrou adequado para dois dos três subgrupos de produtos analisados. As métricas para medição do desempenho preditivo do modelo utilizadas foram o APE (absloute percentual errors ou erro percentual absoluto) e o MAPE* (média absoluta percentual dos erros ajustada). Foram considerados dois horizontes de previsão, seis e oito semanas. O desempenho do modelo conforme a métrica APE para seis semanas de horizonte de previsão foi de 55,199 para o modelo e de 207,511 para o modelo de previsão original. Já para oito semanas de horizonte de previsão foi de 51,232 para o modelo e de 93,212 para o modelo de previsão original. Conforme a métrica MAPE* para seis semanas de horizonte de previsão, o modelo apresentou resultados de 87,598 e o modelo de previsão original apresentou 239,777. E para oito semanas de horizonte de previsão o resultado foi de 88,454 para o modelo e de 167,515 para o modelo de previsão original. Como o modelo foi aplicado somente a um caso, o mesmo não pode ser considerado como validado. Não se pode esperar que os mesmos resultados sejam encontrados em casos diferentes. / For fashion products, the demand is very unpredictable and life cycle of products is short. Retailers are required to make decisions in the assortment and quantities of purchases and inventory a long time before the time of sale, when only limited and inaccurate information is available. Decisions are made relying primarily on qualitative data and subjective issues. Errors in demand forecast associated with this model of decision-making can approach 50%. However, demand forecasts can be improved by updating the predictions based on early sales. In this context, the aim of this work is to propose a demand forecast model based on learning with early sales for a footwear retailer supply chain. The model was applied in a Brazilian footwear retailer in the 2013/2014 Summer Collection. The demand forecasting model was proposed in two stages: (i) the first stage that used historical data aggregated by subgroup, considering product sales per store; and (ii) the second stage that used data from early sales to disaggregate the demand forecast into products and colors. To generate long-term forecast the logistic model was used. The Weekly Increment Proportion (WIP), which is the weekly demand forecast per subgroup divided by the number of products sold, was used as input data to decompose the demand forecast into products and colors. In addition to this information, the other entries are the quantity sold in the first week and the quantity of products in stock. Modifying the inventory turnover calculation to include WIP, we have the updated demand forecast. The forecast also considers the substitution demand and broken grade. The results demonstrated that the demand forecast model based on learning with early sales obtained higher results than original demand forecast model. The long-term forecast model was adequate for two of the three product subgroups analyzed. The metrics for measuring the predictive performance of the model used were APE (absolute percentual errors) and the MAPE* (adjusted mean absolute percentage error). Two forecast horizons were considered, six and eight weeks. The model performance according to the metric APE forecasting six weeks was 55,199 for the model and 207,511 for the original model prediction. Forecasting eight weeks it was 51,232 for the model and 93.212 for the original model prediction. According to the metric MAPE* forecasting six weeks, the model presented a result of 87.598 and the original model presented 239.777. And forecasting eight weeks the result was 88.454 for the model and 167.515 for the original model prediction. As the model was applied to only one case, it cannot be considered validated. The same results are not expected in different cases.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-04-28T12:47:41Z No. of bitstreams: 1 FILIPE BORTOLINI_.pdf: 6329595 bytes, checksum: 3dd8331791bb827a0806c8da5947b553 (MD5) / Made available in DSpace on 2016-04-28T12:47:41Z (GMT). No. of bitstreams: 1 FILIPE BORTOLINI_.pdf: 6329595 bytes, checksum: 3dd8331791bb827a0806c8da5947b553 (MD5) Previous issue date: 2015-11-20 / Nenhuma / A melhoria no planejamento de operações é uma das preocupações constantes das refinarias de petróleo, e a gestão eficiente dos estoques em parques de tancagem é um ponto fundamental nesse contexto. No entanto, são poucos os trabalhos que tratam especificamente deste assunto e as ferramentas de simulação existentes são caras e não refletem a realidade de muitas refinarias. A gestão ineficiente ou o dimensionamento inadequado dos parques de tancagem, por sua vez, podem gerar uma série de prejuízos. Um parque superdimensionado gera custos de gestão e manutenção, além dos custos do estoque. Um parque subdimensionado pode gerar perdas devido a desabastecimentos e degradação de produtos, entre outros. Às situações em que o subdimensionamento gera impactos na produção, com ou sem perdas financeiras, dá-se a denominação de stress em parques de tancagem. Esse trabalho descreve a implantação de uma ferramenta que possibilita a quantificação do stress em parques de tancagem. Essa quantificação é feita com o apoio de uma heurística baseada em dados relativos às movimentações, manutenções e níveis de estoque dos tanques. Também descreve a forma de cálculo de cinquenta e nove variáveis relacionadas às movimentações dos tanques. A influência que essas variáveis têm na formação de situações de stress foi analisada através do uso de redes neurais artificiais. Essa influência foi quantificada em cinco diferentes cenários, considerando-se a existência ou não de um ciclo de certificação de produto e a natureza das variáveis analisadas. Como resultado, identifica-se que as variáveis relacionadas ao tempo de esvaziamento, tempo de tanque parado em nível baixo e tempo de enchimento são as prevalentes na criação de situações de stress em parques de tancagem no contexto analisado. Também são mapeados e formalizados os fluxos dos algoritmos para determinação das etapas do ciclo de um tanque, e é definida uma fórmula para a determinação do nível de stress em um parque de tancagem em um determinado período de tempo. / The improvement in operations planning is a constant concern of oil refineries, and the efficient management of inventories in tank farm sites is a key point in this context. However, there are few studies that deal specifically with this issue and existing simulation tools are expensive and do not reflect the reality of many refineries. The inefficient management or improper sizing of tank farm sites, in turn, can generate significant financial losses. A oversized tank farm generates management and maintenance costs, in addition to inventory costs. An undersized tank farm can generate losses due to shortages and degradation of products, among others. The situations in which the undersizing generates impact in operations, with or without financial losses, is defined as stress in tank farm sites. The present study describes the implementation of a tool that allows the quantification of stress in tank farm sites. This measurement is made using a heuristic based on data on the inventory movimentation, maintenance status and inventory levels of the tanks. It also describes the calculation method of fifty-nine variables related to the movimentation of inventory. The influence of these variables on the formation of stress situations was analyzed using artificial neural networks. This influence was quantified in five different scenarios, considering whether or not a product certification cycle and the nature of the variables. As a result, it is identified that the variables related to emptying time, tank downtime at low level and fill time are prevalent in creating stressful situations in tank farm sites in the analyzed context. They are also mapped and formalized flows of algorithms to determine the stages of a tank cycle, and is defined a formula for determining the stress level in a tankage park at a given time.

The concept of inventory control has been around since the early 20th century and it’s constantly evolving. The importance of inventory management and supply chain management is clear, and companies are constantly trying to evolve their systems and ways of handling inventory control. By having a proper inventory control system with adequate inventory record audits, a company could potentially have several benefits such as reduced tied-up capital, reduced holding costs, reduced/redistributed work hours, better automation and more. Most organisations and companies have some form of inventory control, however not all have full control of their inventory. This includes automatic inventory balance updates, package traceability, automatic replenishment systems and more. To implement these ideas, a company would need to foremost find what factors are currently hindering them from obtaining this and consequently being able to adjust their factors. Since there are several ways to obtain an automatic inventory record update that is adequate, multiple proposals are discussed in this thesis project. This thesis project assessed what the necessary steps that a company needs to perform are through a case study at Scania CV Engine and a benchmarking at Scania Production Angers. Through a collection of scientific literature and empirical data, an attempt to identify the factors that determine whether a company can implement full inventory control or not was made. As a supplement to this, this thesis project also looked over what type of consequences an implementation of full inventory control could have in a company, both when it comes to purely systemic consequences as well as economic consequences. / Begreppet saldokontroll har cirkulerat sedan början av 1900-talet och teorierna utvecklas ständigt. Betydelsen av lagerstyrning och Supply Chain Management är idag tydlig och företag försöker ständigt utveckla sina system och sätt att hantera saldokontroll på. Genom att ha ordentlig saldokontroll med adekvata lagerregistreringsrevisioner kan ett företag potentiellt få flertalet fördelar som till exempel reducerat bundet kapital, minskade innehavskostnader, reducerade eller omfördelade arbetstimmar, bättre automatisering och mera. De flesta organisationer och företag har någon form av lagerkontroll, men inte alla har 100% kontroll över sina inventeringar. Detta inkluderar automatiska lagerrevisioner, spårbarhet av paket, automatiska påfyllningssystem och mer. För att genomföra dessa idéer måste ett företag framför allt finna vilka faktorer som för närvarande förhindrar dem från att uppnå 100% saldokontroll och följaktligen kunna justera dessa faktorer. Eftersom det finns flera sätt att uppnå automatiska revisioner av inventeringen som är proper så diskuteras flera förslag i denna avhandling. Denna avhandling försöker bedöma vilka nödvändiga steg som ett företag behöver genomföra är genom en utförd fallstudie på Scania CV Engine tillsammans med en benchmarking på Scania Production Angers. Genom en samling av vetenskapliga studier och empiriska data från fallstudien gjordes ett försök att identifiera de faktorer som avgöra om ett företag kan implementera 100% saldokontroll eller inte. Som ett komplement till detta ser denna rapport även över vilken typ av konsekvenser en sådan implementering kan innebära, båda när det gäller rent systematiska förändringar samt ekonomiska förändringar.

This Record of Study describes the Doctor of Engineering (DE) internship experience at the Supply Chain Systems Laboratory (SCSL) at Texas A&M University. The objective of the internship was to design and develop automation tools to streamline lab operations related to inventory management projects and during that process adapt and/or extend theoretical inventory models according to real-world business complexity and data integrity problems. A holistic approach to automation was taken to satisfy both short-term and long-term needs subject to organizational constraints. A comprehensive software productivity tool was designed and developed that considerably reduced time and effort spent on non-value adding activities. This resulted in standardizing and streamlining data analysis related activities. Real-world factors that significantly influence the data analysis process were identified and incorporated into model specifications. This helped develop an operational inventory management model that accounted for business complexity and data integrity issues commonly encountered during implementation. Many organizational issues including new business strategies, human resources, administration, and project management were also addressed during the course of the internship.

ABSTRACT Title: Working Capital Management in Telecommunication sector: A case study of VGC telecoms Author: Gbenga Segun Akinwande Supervisor: Anders Hederstierna Department: School of Management, Blekinge Institute of Technology Course: Master’s thesis in business administration, 15 credits (ECTS). Background and Problem Discussion: The efficient management of working capital is very vital for a business survival. This is premised on the fact having too much working capital signifies inefficiency, whereas too little cash at hand signifies that the survival of business is shaky. Purpose: The purpose of this research is to study the working capital management in the small and medium scale businesses, using VGC Telecoms Company as a case study, so as to establish factors influencing working capital performance; examine how cash management, inventory management and trade credit management affects working capital management; company effectiveness in converting working capital to ready money; how working capital management impacts on the problem of slow development and to offer recommendations on possible ways of improving working capital management Method: Literatures bordering on different areas of working capital management were reviewed. Thus, this research employed qualitative and quantitative analysis; and semi- structured questions were drafted based on the issues raised from the review of various literatures. In addition, materials from journal articles, textbooks, working papers and industry practitioners are put into consideration. The use of internet and e-mails to send out questions were explored where appropriate. Analysis on the company’s financial statement was carried out in order to verify my findings. Theory: In this research, the theory section looks at various concepts that come up when analyzing the consequences of working capital management for company value and the factors that influence a company’s working capital management performance. I have therefore chosen the most common concept for the theory section. I have also tried to create a theoretical understanding for the company’s sensitivity to a workable WCM policy Analysis: In the analysis of the research findings, I employed qualitative approach to the data analysis whereby the impacts of the poor WCM on the company were discussed in depth. Conclusion: The findings corroborate the postulation of Weston et al that a company’s investment in working capital is a substantial percentage of its total investment. In case of VGC Telecoms, it is as high as 65 percent. An inefficient and ineffective management of this investment will result in slow pace of development and ultimately to the business failure. The performances of the company in the different spheres of working capital management were scored as follows:- • Cash management – 65.4 percent • Inventory management - 78.6 percent • Trade credit management and financing decisions - 60.0 percent This is an average performance of 68 percent. That is, the company’s performance is above average. This is a good performance. The financial statements as interpreted reinforce the validity of this result. The liquidity ratios are high; the collection period is short; and the cash cycle is not quite expansive. This makes it possible to sustain sufficient cash flow for the smooth running of the business. The management of working capital impacts on liquidity, investment portfolio and profitability. All these three factors are decisive in the growth or failure of a business. Hence, good performances in working capital management affects these decisive factors favourably and thus, contribute to growth and success of the business.

Introduction: Nowadays beverage companies must focus on maintaining healthy finishedgoods inventory stocks in order to be able to decrease inventory costs, meet customerrequirements and to obtain competitive advantage. However many beverage SMEdon’t have an accurate planning and forecasting to manufacturing inventories. Thereforethey often face the problem of optimization in inventory management due to several differentreasons. As a result, company loses its competitiveness. Thus, there is a need tocoordinate Inventory activities of beverage SMEs to improve inventories’ planning. The purpose of this study is to analyze how inventory management is organized in a small Chinese beverage company. Frame of reference: This research is based on the theoretical framework relates with InventoryManagement (IM) and Retailer-managed inventory (RMI), vendor-managed inventory(VMI) and Collaborative Planning, Forecasting and Replenishment (CPFR).Empirical Data were collected through personal interviews and organization documents. Methodology: The research strategy for this paper is a single case study. This strategy allows investigating topic in its real life context. The inductive approach is used for this research based on qualitative data. The major source of data collection was semi-structured interviews and the company's documents. For analyzing data categorization approach was applied. Conclusion: The study found that inventory management theories presented in scientificliteratures are used in practice. To achieve better inventory management for beverageSMEs, the authors summarize four importance parameters based on literatures and findings.The authors also provide some suggestions based on the importance parameters inthe conclusion to optimize the case company’s inventory management.

The objective of this thesis was to analyze the activities of a company engaged in the storage and distribution of goods for ?Jednota? stores for a period of one calendar year, to identify potential weaknesses and to suggest measures for their removal. Theoretical knowledge from professional literature was applied in the actual part of the thesis. The analysis of inventory management was conducted with three selected items from the ?A? category for which economically favourable ordering quantity was calculated using the Camp formula; minimum safety stock of 90% and 95% was determined and the point of order was calculated too. These model calculations were then compared with the actual data for all three items: still table water ?Klasik? (2 litres), whole-meal wheat flour ?Klasik? and ?Tuzemák Jindřichohradecký? (0.5 litre).

Independent de la performance remarquable accomplie par la logistique d’aujourd’hui, les réseaux actuels sont majoritairement dédiés à un acteur et donc très peu interconnectés. Cette fragmentation conduit une difficulté de mutualisation des flux et dès lors à une efficacité limitée. Ces organisations dédiées et hétérogènes sont de plus en plus challengées par les nouveaux défis d’aujourd’hui posés à l’efficacité, l’efficience et la résilience. Pour répondre à cet antagonisme, un innovant concept logistique - l’Internet Physique (PI) - a été proposé. Dans ce système, les infrastructures et les moyens de transport peuvent être organisés de façon dynamique et attribués à court ou à long terme en fonction des besoins. Par conséquent, les décisions des opérations logistiques peuvent être prises de façon dynamique, agile, et donc de manière plus optimale. Cette thèse concentre les perspectives de PI concernant la gestion de stocks et du transport par rapport aux défis de l’efficacité et de la résilience.Comme l’étude de l’efficacité de PI par rapport au transport a été déjà effectuée, le premier objectif de cette recherche est d’explorer les potentiels de l’interconnexion des réseaux dans la gestion de stocks, qui n’a par encore été adressé. À cette fin, nous examinons d'abord les trois nouvelles pratiques apportées par PI : 1) les stocks distribués à proximité des clients finaux; 2) le transbordement de stocks entre les hubs; 3) de multiples options dynamiques de sélection de la source pour chaque commande. Deux modèles de gestion de stocks correspondants sont proposés. Cette étude sert de guide pour des décisions de stockage pour les vendeurs dans un tel système logistique ouvert.Après l’analyse d’efficacité de PI, la deuxième partie de cette thèse concerne la résilience des modèles de stockage et de transport dans PI confrontés à des interruptions dans la chaîne logistique. On a étendu les modèles de stockage et de transport avec interruptions imprévisibles dans les infrastructures telles que l’usine ou les hubs. Des stratégies différentes sont développées pour atténuer les risques de perturbation des flux. Des études numériques sont effectuées pour évaluer la performance des modèles proposés.En résumé, cette recherche est la première qui étudie le potentiel de l’Internet Physique pour la gestion de stock et la résilience de ce système. D’après les résultats, il n’y a aucun doute que le PI change le design de chaîne logistique d’aujourd’hui et améliore la performance de gestion de logistique à la fois en efficience et en résilience. / Irrespective of significant performance achieved, today’s logistics networks are overwhelmingly dedicated to an actor and therefore poorly interconnected. This fragmentation exhibits inevitable inefficiency and needs to be changed in respond to today’s new arising challenges in efficiency and resilience. To solve this antagonism, an innovative concept - Physical Internet (PI) - has been proposed which is a fully interconnected, open, dynamic logistics system. In such a system, the facilities and means of transportation can be dynamically organized and allocated in the short-term or long-term according to the economic environment. As a result, decisions can be made dynamically, agilely, and thus optimally. This thesis studies the perspectives of the PI to inventory management and transportation regarding the challenges in efficiency and resilience.As the efficiency of the PI to transportation has been carried out in literature, the first objective of this thesis is to explore the potentials of the PI to inventory management. To this end, we firstly qualitatively examine the new practices brought by the PI and conclude three main characteristics: 1) Distributed stocks near end customers; 2) Transshipment of inventories; and 3) multiple dynamic source options. Corresponding inventory models and solutions are proposed and evaluated with numerical experiments in Fast Moving Consumer Goods (FMCG). This part of study gives a guideline for the vendors applying the PI to make inventory decisions in such an open logistic system.The second objective is to analyze the resilience of the proposed PI enabled inventory and transportation model confronted to disruptions. The proposed inventory and transportation model are extended with different disruptions at facilities including plants and hubs. Different disruption strategies are developed. Numerical studies in FMCG are carried out.In a word, this research investigates the inventory management in the PI and the resilience of PI enabled logistics models. It is the first time such a work is done and it should be upfront. From the results of studies, there is no doubt that the PI changes today’s supply chains design and improve the performance of supply chain management both in efficiency, effectiveness and resilience.

Made available in DSpace on 2014-12-17T14:52:58Z (GMT). No. of bitstreams: 1 RobertoKMF_DISSERT.pdf: 1712911 bytes, checksum: 4a2d9da3d58d19eb0b246c2f5c1cf027 (MD5) Previous issue date: 2010-12-22 / This work searches to offer a model to improve spare parts stock management for companies of urban passenger transport by bus, with the consequent progress in their maintenance management. Also known as MRO items (Maintenance, Repair and Operations), these spare parts, according their consumption and demand features, cost, criticity to operation, lead-time, quantity of suppliers, among other parameters, shouldn?t have managed their inventory like normal production items (work in process e final products), that because their features, are managed by more predictable models based, for example, in economic order quantity. In the case specifically of companies of urban passenger transport by bus, items MRO have significant importance in their assets and a bad management of these inventories can cause serious losses to company, leading it even bankrupticy business, in more severe situations which missing spare part provokes vehicles shutdown indefinitely. Given slight attention to the issue, which translates in little literature available about it when compared to that literature about normal items stocks, and due the fact that MRO items be critical to bus urban transport of passengers companies?, it is necessary, so, deepen in this theme searching to give technical and scientific subsidies to companies that work, in many times, empirically, with these so decisive inputs to their business. As a typical portfolio problem, in which there are n items, separated into critical and noncritical, while competing for the same resource, it was developed a new algorithm to aid in a better inventory management of spare parts used only in corrective maintenance (whose failures are unpredictable and random), by analyzing the cost-benefit ratio, which compares the level of service versus cost of each item. The model was tested in a company of urban passenger transport by bus from the city of Natal, who anonymously provided their real data to application in this work / O trabalho busca oferecer um modelo para melhor gest?o do estoque de pe?as de reposi??o para empresas de transporte urbano de passageiros, com a conseq?ente melhoria na gest?o das suas manuten??es. Tamb?m conhecidos como itens MRO (Manuten??o, Reparo e Opera??es), estas pe?as de reposi??o, em fun??o das suas caracter?sticas de consumo e demanda, custo, criticidade para a opera??o, tempo de ressuprimento, quantidade de fornecedores, entre outros par?metros, n?o devem ter seus estoques geridos como itens normais de produ??o (bens intermedi?rios e produtos acabados), que pelas suas caracter?sticas, s?o regidos por modelos mais previs?veis baseados, por exemplo, no lote econ?mico de compra. Em se tratando especificamente de empresa de transporte urbano de passageiros por ?nibus, os itens MRO t?m peso significativo nos seus ativos e a m? gest?o deste estoque pode causar s?rios preju?zos ? companhia, levando-a, em situa??es mais graves em que a pe?a faltante resulte em parada de ve?culos por tempo indeterminado, at? ? fal?ncia do neg?cio. Face ? discreta aten??o ao tema, o que se traduz na pouca literatura dispon?vel sobre o mesmo quando comparada ?quela relacionada aos estoques de itens de produ??o, e devido ao fato dos itens MRO serem cr?ticos para as empresas de transporte urbano de passageiros, faz-se necess?rio, pois, o aprofundamento no assunto buscando dar subs?dios t?cnico-cient?ficos ?s firmas que trabalham, muitas vezes de forma emp?rica, com estes insumos t?o decisivos para o seu neg?cio. Tendo-se um t?pico problema de portf?lio, no qual existem n itens, segregados em cr?ticos e n?o-cr?ticos, competindo simultaneamente pelo mesmo recurso, foi desenvolvido um novo algoritmo para auxiliar na melhor gest?o do estoque de pe?as de reposi??o utilizadas somente em manuten??es corretivas (cujas falhas s?o imprevis?veis e aleat?rias), atrav?s da an?lise da rela??o custo-benef?cio, onde comparam-se n?vel de servi?o versus custo de cada item. O modelo foi testado em uma empresa de transporte urbano de passageiros por ?nibus da cidade de Natal, que anonimamente, forneceu seus dados reais para aplica??o neste trabalho