Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains ix, 142 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 25).

Stanley B. Gershwin. / "July 1983" / Bibliography: leaves 10-11. / "DAAK11-82-K-0018"

Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: This report presents the findings of a study that started as an evaluation of the possible implementation of the Options Inventory Management Model (OIMM), developed by van Wijck and Bekker [4], at DaimlerChrysler South Africa (DCSA). The OIMM System was developed as a possible alternative to the SAP-MRP System to ensure a high Customer Service Level, with the lowest possible inventory level, under the 10 Day Option Freeze Environment. DCSA indicated that although the OIMM System may be an ideal solution, in terms of optimising Plant Inventory levels whilst maximising Customer Service Levels, the practical problems associated with the possible implementation of this system would outweigh the associated benefits. This being the case, a directive was given to investigate the SAP-MRP System’s ability to provide a high Customer Service Level under the 10 Day Option Freeze Environment and not to pursue the OIMM implementation option. The objectives of this directive were to evaluate and establish the performance capabilities of the SAPMRP System under the 10 Day Option Freeze Environment as well as develop a system to aid in the customisation of the system. Design of Experiments (DOE) was utilised to plan the evaluation procedure and to ensure that a consistent approach was followed. The DOE generated huge amounts of output data that represented the Usage Category Behaviour Characteristics of the SAP-MRP System. Regression Analysis was utilised to investigate this data. A part-by-part analysis was avoided and the analysis approach followed presented results that could be applied to almost the entire range of parts, excluding bulk parts, at DCSA. The results showed that Coverage Profile alone could be used as a proactive inventory management tool to ensure maximum Customer Service Level. The Regression Analysis revealed that various combinations of Safety Time, Minimum, and Target Coverage resulted in similar or equal Avg. Plant Inventories, Avg. Number of Orders, and Avg. Order Sizes. These findings were used to develop a Decision Support Tool that could be used by DCSA when evaluating the resultant changes caused by the proposed changes in the aforementioned Input Parameters. / AFRIKAANSE OPSOMMING: Hierdie verslag stel die bevindinge van ‘n studie voor wat begin het met die evaluering van die moontlike implementering van die “Options Inventory Management Model” (OIMM), ontwikkel vir DaimlerChrysler (DCSA) deur van Wijck en Bekker [4]. Die OIMM sisteem was ontwikkel as ‘n moontlike alternatief vir die SAP-MRP sisteem om ‘n hoë verbruikersdiensvlak tesame met die laagste moontlike voorraadvlak in ‘n 10-dag opsie-vries omgewing te verseker. DCSA het aangedui dat, hoewel die OIMM sisteem ‘n ideale oplossing bleik te wees in terme van die optimisering van fabriek-voorraadvlakke tesame met die verbruikersdiensvlakke, die praktiese probleme wat met die moontlike implimentering daarvan geassosieer word, die geassosieerde voordele oorskry. Daar is dus opdrag gegee om die SAP-MRP sisteem se vermoë om hoë verbruikersdiensvlakke in die 10-dag opsie-vries omgewing te lewer te ondersoek en sodoende nie die implimentering van die OIMM sisteem te vervolg nie. Die doelwitte van hierdie opdrag was die evaluering en vestiging van die prestasievermoëns van die SAP-MRP sisteem in die 10-dag opsie-vries omgewing, asook om ‘n sisteem te ontwikkel wat as hulpmiddel kan dien in die geïndividualiseerde aanpassingsoptimisering daarvan. ‘n Eksperimentele Ontwerp (DOE) is gebruik in die beplanning van die evalueringsprosedure en ook om te verseker dat ‘n konstante benadering gevolg is. Die DOE het ‘n groot hoeveelheid uitsetdata genereer wat die prestasie van die SAP-MRP sisteem se gedragseienskappe voorgestel het. Regressie-analise is uitgevoer om die data te ondersoek. Onderdeel-by-onderdeel analise is vermy en die analise-benadering wat gevolg is het resultate gelewer wat toegepas kon word vir omtrent die hele reeks onderdele by DCSA, uitsluitende onderdele wat in grootmaat aangekoop word. Die resultate het gewys dat die “Coverage Profile” alleen gebruik kan word as ‘n pro-aktiewe voorraadbestuur hulpmiddel om maksimum verbruikersdiensvlakke te verseker. Die regressie-analise het getoon dat verskeie kombinasies van “Safety Time,” “Minimum” en “Target Coverage” gelei het tot dieselfde hoeveelheid fabrieks-voorraad, bestellingsvrystellings en bestellingsgroottes. Hierdie tendense is toegepas in die ontwikkeling van ‘n ondersteunende besluitnemingshulpmiddel wat deur DCSA gebruik sou kon word in die evaluering van die veranderinge wat onstaan vanweë die voorgestelde verandering in die voorafgenoemde insetparameters.

Orientador: Fernando Bernardi de Souza / Banca: Andrea da Silva Meyer / Banca: Gilberto Miller Devos Ganga / Resumo: O gerenciamento de estoques em cadeias de suprimentos vem enfrentando diversos problemas, como baixa rotatividade, altos investimentos em estoque, vendas perdidas por rupturas e alto índice de obsolescência dos produtos estocados. Assim, esta pesquisa tem o objetivo de avaliar a efetividade da técnica Gerenciamento Dinâmico do Pulmão (Dynamic Buffer Management - DBM) como forma de preservar a disponibilidade de produtos destinados à entrega imediata em ambientes que adotem a solução de distribuição e reposição puxada da Teoria das Restrições. Para tanto, foram realizadas simulações no software ProModel utilizando dados estocásticos para o tempo de reposição e cenários com diferentes combinações de demanda. Esta, por sua vez, pode se comportar de duas formas: i) média sem tendência com dois níveis de coeficiente de variação e ii) média com tendência sazonal com dois níveis de intensidade. Dois algoritmos do DBM foram modelados segundo seus princípios constatados na literatura e combinados com parâmetros para ajuste dinâmico do estoque alvo. Os modelos foram avaliados por meio dos seguintes indicadores: fill rate, estoque médio no sistema e rotatividade por atendimento imediato da demanda. Os resultados indicam que para a demanda média sem tendência, desativar o DBM e manter um nível sensato de estoque alvo no sistema inibe ajustes indevidos e garante um bom desempenho do modelo. Contudo, para a demanda média com tendência sazonal, o DBM é altamente recomendado para assegurar a... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Inventory management in supply chains has faced several problems, such as low turnover, high inventory investments, lost sales due to disruptions, and high obsolescence of stored products. Thus, this research aims to evaluate the effectiveness of the Dynamic Buffer Management (DBM) technique as a way of preserving the availability of products destined for immediate delivery in environments that adopt the distribution solution and pull replenishment of the Theory of Constraints (TOC). For that, simulations were performed in the ProModel software using stochastic data for the replenishment time and scenarios with different combinations of demand. This, in turn, can behave in two ways: i) average without trend with two levels of coefficient of variation and ii) average with seasonal trend with two levels of intensity. Two DBM algorithms were modeled according to their principles found in the literature and combined with parameters for dynamic adjustment of the target level. The models were evaluated through the following indicators: fill rate, average inventory in the system and turnover for immediate demand response. The results indicate that for the average demand without trend, disabling DBM and maintaining a sensible level of target level in the system inhibits undue adjustments and ensures good model performance. However, for average demand with seasonal trend, DBM is highly recommended to ensure system performance and adjust inventory levels as the demand pattern changes. / Mestre

Orientador: Adriana Cristina Cherri Nicola / Co-orientador: Edméa Cássia Baptista / Banca: Franklina Maria Bragion de Toledo / Banca: Charbel José Chappetta Jabbour / Resumo: Este trabalho, tendo em vista as teorias de Ecological Modernization e Produção Mais Limpa (P+L), relaciona sustentabilidade e pesquisa operacional por meio de uma variação do problema de corte de estoque com sobras aproveitáveis (PCESA). No PCESA um conjunto de objetos padronizados (comprados de fornecedores) ou não padronizados (retalhos gerados em processos de corte anteriores), disponíveis em estoque, devem ser cortados em um conjunto de itens com dimensões e quantidades especificadas. Este problema tem por finalidade determinar a melhor forma de cortar os objetos de modo a otimizar uma função objetivo e considerando que uma determinada quantidade de retalhos pode retornar ao estoque para atender futuras demandas. Diferente dos trabalhos propostos na literatura, neste trabalho, o PCSE será resolvido, porém, os retalhos em estoque além de serem utilizados, poderão ser vendidos se esta opção for a mais atrativa. Este problema, denominado de problema de corte de estoque com sobras aproveitáveis e venda de retalhos (PCESAVR), tem por objetivo maximizar o lucro. Para modelar o PCESAVR, alterações foram realizadas em um modelo matemático proposto na literatura e, para resolvê-lo, foi utilizado o método simplex com geração de colunas. Como a solução obtida para este problema não é inteira, dois procedimentos heurísticos, que também consideram o aproveitamento de sobras, foram propostos. Testes computacionais foram realizados com exemplares gerados aleatoriamente considerando problemas estatísticos e uma simulação por períodos de tempo, na qual os retalhos gerados em um período ficam disponíveis para o uso e/ou venda no período seguinte. Com esses testes, verificou-se o bom desempenho da estratégia proposta. Devido às particularidades dessa estratégia, também se fez uma análise e discutiu-se os resultados considerando implicações na P+L, que é uma estratégia que pretende integrar objetivos ambientais aos.. / Abstract: Considering the theories of Ecological Modernization and Cleaner Production (CP), this work relates the sustainability and the operational research through a variation of cutting stock problem with usable leftovers (CSPUL). In the CSPUL a set of standard objects (boutht from suppliers) or non-standard objects (retails generated in previous cutting processes), which area available in stock, must be cut in order to produce a set of demanded items with dimensions and specifed quantities. The objective consists of determining the best way to cut the objects optimizing an objective function and considering that a certain amount of retails can return to the stock to meet future demands. Differently of the work, the CSPUL will be solved, however, retails in stock in addition to being used, they can be sold of this option is more attractive. This problem is named of cutting stock problem with usable leftovers and sale retails (CSPULSR) and has the objective of maximizing the profit. To model the CSPULSR, was modified a mathematical model proposed in the literature and, to solve it, the simplex method with column generation was used. As the obtained solution to this problem is not integer, were proposed two heuristic procedures that also consider the usable leftovers. Computational tests were performed with randomly generated instances considering static problems and a simulation by periods of time, in which retails generated in a period stay available for use and/or sale of the next period. With these tests, very good performance of the proposed strategy was verified. Due to the particularities of this strategy, also was realized an analysis and discussed the results considering implications for CP, which is a strategy that intends to integrate environmental objective into industrial processes, in order to reduce the amount of waste and emissions. It also aligns the theory of Ecological Modernization as it seeks to reduce the environmental... / Mestre

The study sought to investigate the use of RFID technology as inventory control in academic libraries in South Africa, with a focus on the University of South Africa and the University of Fort Hare libraries. The objectives of the study were to describe the current inventory control practices at the libraries of the University of South Africa and the University of Fort Hare in order to determine the infrastructure required for the use of RFID for inventory control for the University of Fort Hare’s libraries; to evaluate the benefits of RFID technologies, in order to gain a competitive advantage for the University of South Africa’s and the University of Fort Hare’s libraries; to identify the challenges associated with adopting RFID technology, as experienced by the libraries of the University of South Africa and the University of Fort Hare. The study adopted both the quantitative and qualitative research approaches. The researcher followed a rigorous methodological path that began with a thorough literature review coupled with the careful and thoughtful posing of research questions and objectives. A purposive sample of forty (40) respondents was selected from the library staff from both the University of South Africa and University of Fort Harelibraries. The collected data were analysed using the Statistical Package for Social Sciences 23 (SPSS 23) and Microsoft Excel 2010. The findings of the study revealed reasons for both academic libraries to invest in RFID technology; these reasons include RFID’s ability to deliver self-service options, inventory control, improved reader access and improved security. The challenges related to the implementation of RFID technology are also related to staff not being rewarded by library management for being innovative; the difficulty of staff learning new technology; the staff’s inability to generate new ideas for the library; and the staff not being able to share knowledge with each other. Further research needs to be conducted by library RFID vendors in order to meet the need, of academic libraries, for RFID inventory control. RFID hardware and software (API software) should be subjected to further investigation for the purposes of research and development. Libraries should work closer with RFID vendors so as to trial and test hardware and software.

Made available in DSpace on 2016-01-13T13:27:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-07-03. Added 1 bitstream(s) on 2016-01-13T13:33:07Z : No. of bitstreams: 1 000854297.pdf: 1414696 bytes, checksum: cc69b6cafb81fe878c895e95b0855ecd (MD5) / O forte cenário competitivo entre as organizações motiva-as a serem mais eficientes em reduzirem custos operacionais, sem comprometer a qualidade dos produtos ou serviços prestados. Essa redução de custos envolve vários setores, entre eles, a manutenção dos ativos industriais, que têm como função primária manter a capacidade produtiva de uma organização. O impacto dessas reduções pode gerar restrições severas, como paradas não planejadas e redução do nível de serviço, como as que ocorrem por ruptura do estoque de sobressalentes de MRO ()Manutenção, Reparo e Operação). Por outro lado, se a falta de estoque de itens denominados slow moving, intermitentes, de alto custo agregado causa perda direta e lucro cessante, o erro de previsibilidade da demanda pode significar a imobilizaçõ de alto valor de capital em estoques, gerando um alto custo de oportunidade, representado pela taxa de juros aplicada sobre o valor dos estoques. Esse trade off é o propósito desta pesquisa, em que se faz um estudo de caso com dados reais de demandas e custos de empresas que possuem operações com ativos industriais, utilizando-se a distribuição de Poisson no estudo do comportamento de variável custo total. O resultado obtido foi uma relação direta entre a variável custo total e o nível de serviço, mostrando que há um ponto de mínimo na curva custo total com o aumento da quantidade de itens projetados, determinando o ponto de menor custo de estoque. A conclusão na observação dessas variáveis é que o menor custo total nem sempre representa o melhor nível de serviço / The strong competitive environment between organizations motivate them to be more efficient to reduce operating costs without compromising the products or services quality. This cost reduction involves various sectors, including the maintenance of industrial assets, whose its primary function is to maintain the productive capacity of an organization. The impact of these reductions can lead to severe restrinctions, such as unplanned downtime and reduced fill rate, which occurs due to rupture of MRO stock (Maintenance, Repair and Operation). On the other hand, the lack of inventory items denominated slow moving, intermittent, high added cost cause direct profits losses, the demand predictability error can mean the inmobilization of high-value capital in inventory, thus generating a high opportunity cost, represented by the rate applied to the inventories values. This trade of is the purpose of this research, which is a case study with real data demands and costs of companies that have operations using industrial assets, using the Poisson distribution, and the study of the variable total cost behavior. The results obtained was a direct relationship between tha variable total cost and the fill rate showing that there is a minimum point on the curve total cost by increasing the projected amount, determining the point of least cost of stock. The conclusion on the observation of these variables is that the lowest total cost is not always the best level of service

Made available in DSpace on 2016-04-01T17:55:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-11-27. Added 1 bitstream(s) on 2016-04-01T18:01:05Z : No. of bitstreams: 1 000860079.pdf: 1232881 bytes, checksum: 0f5102be19abed6a31301bc6abdb196d (MD5) / Este trabalho, tendo em vista as teorias de Ecological Modernization e Produção Mais Limpa (P+L), relaciona sustentabilidade e pesquisa operacional por meio de uma variação do problema de corte de estoque com sobras aproveitáveis (PCESA). No PCESA um conjunto de objetos padronizados (comprados de fornecedores) ou não padronizados (retalhos gerados em processos de corte anteriores), disponíveis em estoque, devem ser cortados em um conjunto de itens com dimensões e quantidades especificadas. Este problema tem por finalidade determinar a melhor forma de cortar os objetos de modo a otimizar uma função objetivo e considerando que uma determinada quantidade de retalhos pode retornar ao estoque para atender futuras demandas. Diferente dos trabalhos propostos na literatura, neste trabalho, o PCSE será resolvido, porém, os retalhos em estoque além de serem utilizados, poderão ser vendidos se esta opção for a mais atrativa. Este problema, denominado de problema de corte de estoque com sobras aproveitáveis e venda de retalhos (PCESAVR), tem por objetivo maximizar o lucro. Para modelar o PCESAVR, alterações foram realizadas em um modelo matemático proposto na literatura e, para resolvê-lo, foi utilizado o método simplex com geração de colunas. Como a solução obtida para este problema não é inteira, dois procedimentos heurísticos, que também consideram o aproveitamento de sobras, foram propostos. Testes computacionais foram realizados com exemplares gerados aleatoriamente considerando problemas estatísticos e uma simulação por períodos de tempo, na qual os retalhos gerados em um período ficam disponíveis para o uso e/ou venda no período seguinte. Com esses testes, verificou-se o bom desempenho da estratégia proposta. Devido às particularidades dessa estratégia, também se fez uma análise e discutiu-se os resultados considerando implicações na P+L, que é uma estratégia que pretende integrar objetivos ambientais aos.. / Considering the theories of Ecological Modernization and Cleaner Production (CP), this work relates the sustainability and the operational research through a variation of cutting stock problem with usable leftovers (CSPUL). In the CSPUL a set of standard objects (boutht from suppliers) or non-standard objects (retails generated in previous cutting processes), which area available in stock, must be cut in order to produce a set of demanded items with dimensions and specifed quantities. The objective consists of determining the best way to cut the objects optimizing an objective function and considering that a certain amount of retails can return to the stock to meet future demands. Differently of the work, the CSPUL will be solved, however, retails in stock in addition to being used, they can be sold of this option is more attractive. This problem is named of cutting stock problem with usable leftovers and sale retails (CSPULSR) and has the objective of maximizing the profit. To model the CSPULSR, was modified a mathematical model proposed in the literature and, to solve it, the simplex method with column generation was used. As the obtained solution to this problem is not integer, were proposed two heuristic procedures that also consider the usable leftovers. Computational tests were performed with randomly generated instances considering static problems and a simulation by periods of time, in which retails generated in a period stay available for use and/or sale of the next period. With these tests, very good performance of the proposed strategy was verified. Due to the particularities of this strategy, also was realized an analysis and discussed the results considering implications for CP, which is a strategy that intends to integrate environmental objective into industrial processes, in order to reduce the amount of waste and emissions. It also aligns the theory of Ecological Modernization as it seeks to reduce the environmental...

Submitted by PAULO ROBERTO ALVES null (alves.pr@gmail.com) on 2016-09-05T00:58:36Z No. of bitstreams: 1 Impressão.pdf: 3099318 bytes, checksum: 10399fd5ba9dcef5191df580ba15f09b (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-09-06T20:06:32Z (GMT) No. of bitstreams: 1 alves_pr_me_bauru.pdf: 3099318 bytes, checksum: 10399fd5ba9dcef5191df580ba15f09b (MD5) / Made available in DSpace on 2016-09-06T20:06:32Z (GMT). No. of bitstreams: 1 alves_pr_me_bauru.pdf: 3099318 bytes, checksum: 10399fd5ba9dcef5191df580ba15f09b (MD5) Previous issue date: 2016-07-07 / O objetivo desta pesquisa consiste em identificar e analisar as variáveis internas e/ou externas que se caracterizam como sendo fatores na adoção da tecnologia RFID no controle de estoques de materiais, especificamente nas áreas denominadas almoxarifados em usinas pertencentes ao setor sucroalcooleiro no atual cenário produtivo e econômico nacional. A escolha de usinas do setor sucroalcooleiro foi devido a relevância econômica que representou no ano de 2013, 2% do PIB nacional, montante este equivalente a US$ 43 bilhões, e tendo o valor bruto movimentado pela cadeia superior a US$ 100 bilhões. Para tanto foram empregados os métodos de revisão bibliográfica e survey. Como principais resultados foi possível observar que em um universo de 32 respondentes com cargos de liderança, 12,5% dos respondentes desconhecem a tecnologia RFID. De um total de 28 respondentes que demonstraram conhecer a tecnologia, 100% retornaram não ter a tecnologia implementada em suas operações, somente 28,6% entendem que a empresa já tenha avaliado em algum momento a possibilidade de implementação, e 60,7% acreditam que a implementação seja uma operação complexa, demonstrando que estes fatores contribuem negativamente para a adoção da tecnologia nas operações de almoxarifados em usinas. / The objective of this research is to identify and analyze the internal and/or external variables that are characterized as being factors in the adoption of RFID technology in the control materials inventory, specifically in the areas called stockrooms in plants belonging to the sugarcane sector in the current production scenario and national economic. The choice of plants of this sector was due to the economic importance which represented in 2013, 2% of GDP, this amount equivalent to US $ 43 billion, taking the gross busy the upper chain to $ 100 billion. Therefore, we used the methods of literature review and survey. The main results we observed that in a universe of 32 respondents with leadership positions, 12.5% of respondents are unaware of the RFID technology. A total of 28 respondents who knew about the technology, 100% returned not have the technology implemented in its operations, only 28.6% believe that the company has been evaluated at some point the possibility of implementing, and 60.7% believe that implementation is a complex operation, demonstrating that these factors negatively contribute to the adoption of technology in warehouses operations in plants.

Orientador: Edméa Cássia Baptista / Co-orientador: Fernando Bernardi de Souza / Banca: Edilaine Martins Soler / Banca: Sonia Cristina Poltroniere Silva / Resumo: A gestão de estoque pode ser considerada como um dos principais componentes do planejamento e controle da produção. Na literatura acadêmica, inúmeros modelos matemáticos são apresentados para a gestão de estoque, os quais se referem a diferentes aspectos relacionados a essa gestão. O desenvolvimento de modelos de estoque eficientes e a adoção de métodos de otimização adequados para resolução desses modelos são necessários para o suporte à tomada de decisão. Neste trabalho, propõe-se um novo modelo de estoque que considera múltiplos produtos e múltiplas restrições de recursos, explorando o conceito de ponto de reposição e revisão periódica. Este problema é formulado como um problema de otimização não linear inteiro misto. Explora-se para a resolução deste modelo, uma abordagem baseada no método de Branch and Bound com o método de pontos interiores para a resolução dos problemas da árvore de busca. Testes computacionais são realizados com o modelo proposto e o método de resolução adotado. Os resultados obtidos evidenciam os seus potenciais para trabalhar com sistemas de estoque multiprodutos com múltiplas restrições. / Abstract: Inventory management can be considered as one of the main components of planning and production control. In the academic literature, numerous mathematical models are presented for the inventory management, which refer to different aspects related to such a management. The development of efficient inventory models and the adoption of appropriate optimization methods for solving these models are needed to support decision-making. In this work, we propose a new inventory model that considers multiple products and multiple resource constraints, exploring the concept of replacement point and periodic review. This problem is formulated as a mixed integer non-linear optimization problem. For solving this model, an approach based on Branch and Bound method with interior point method for solving the search tree problems is explored. Computational tests are performed with the proposed model and the resolution method adopted. The obtained results show their potential to work with multiproduct inventory systems with multiple constraints. / Mestre