Orientador: Antônio Batocchio / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica. / Made available in DSpace on 2018-08-21T02:21:04Z (GMT). No. of bitstreams: 1 Rabelo_MarceloMaciel_M.pdf: 1566499 bytes, checksum: d76d98f5a72183bd42b5d44157da3aeb (MD5) Previous issue date: 2011 / Resumo: A competitividade mundial está cada vez mais acirrada entre as empresas e a busca de diferenciais para os clientes passa diretamente pelos custos de seus produtos. Países com alta tecnologia de produção e também com elevados custos de produção interna estão optando por obter fontes de fornecimento em regiões onde os custos de produção são baixos e, conseqüentemente, reduzindo muito os custos do produto final sendo assim capazes de aumentar a atratividade para seus produtos. Devido à busca constante pela para redução de custos dos produtos finais, em especial, as empresas sistemistas estão atuando de forma a desenvolver novas fontes de fornecimento na região asiática que oferece preços altamente competitivos. O estudo mostra as relações e os impactos gerados pelo processo de Global Sourcing, as incertezas deste processo na cadeia de suprimentos e seus possíveis impactos na manufatura dos clientes destes componentes. Atualmente as empresas e seus administradores não possuem todos os recursos e conhecimentos necessários para a avaliação e tomada de decisão correta considerando as vantagens e desvantagens entre manter-se com a fonte atual e uma nova, originária da Ásia. Diante deste problema, este trabalho colaborará com os administradores a ter uma visão sobre quais são algumas das principais variáveis existentes neste processo. Como não há uma regra geral, o grande problema para os administradores é escolher a estratégia correta e, quantificar e qualificar seus benefícios podem ser de grande ajuda. O resultado deste trabalho será uma matriz de decisão que considera os três pilares usualmente considerados na escolha de uma fonte com relação à cadeia de fornecimento: compras, logística e qualidade. O objetivo deste trabalho é definir um método para combinar os três pilares usualmente considerados na escolha de uma fonte de fornecimento para indústria de autopeças, são eles: compras, logística e qualidade com o método AHP (Analytic Hierarchy Process) que auxiliará os gestores deste processo na tomada de decisão / Abstract: The global competition is increasingly fierce among companies and the search for differentials passes directly to customers the costs of their products. Countries with high technology production and also have high costs of domestic production are opting for more sources of supply in regions where production costs are low and, consequently, greatly reducing the cost of the final product is thus able to increase their attractiveness to products. Due to the constant search for cost reduction of final products, in particular, the systems are operating companies in order to develop new sources of supply in the Asian region offering highly competitive prices. The study shows the relationships and impacts generated by the process of Global Sourcing, the uncertainties of this process in the supply chain and its possible impacts on customers' manufacturing these components. Now the companies and their managers do not have all the resources and knowledge needed to evaluate and correct decision making considering the advantages and disadvantages of keeping up with the current source and a new, native to Asia. Faced with this problem, this paper will work with managers to gain insight into what are some of the main variables in this process. Since there is a general rule, the big problem for managers is to choose the right strategy, and quantify and qualify its benefits can be of great help. The result of this work is a decision matrix that considers the three pillars usually considered in choosing a source with respect to the supply chain: purchasing, logistics and quality. The objective of this work is to define a method for combining the three pillars usually considered when choosing a supply source for auto parts industry, they are, purchasing, logistics and quality with the AHP method (Analytic Hierarchy Process) to assist managers in this process of decision making / Mestrado / Manufatura / Mestre em Engenharia Automobilistica

Le travail de recherche réalisé dans le cadre de cette thèse introduit une nouvelle approche thermomécanique pour la modélisation du procédé de taillage à la fraise-mère et la maitrise de la précision géométrique et la qualité des pièces fabriquées. Le processus de coupe de la génération des dentures des couronnes de grandes dimensions a été simulé pour la prédiction des efforts de coupe. Le calcul de ces efforts s’est basé sur trois phases : une phase de simulation de l’'intersection géométrique entre l'outil et la pièce moyennant une simulation de la cinématique du procédé par le logiciel CATIA, une phase de simulation numérique ALE (Approche Eulérienne-Lagrangienne) 2D de la coupe orthogonale, et une dernière phase dite ‘simulation mécanistique’ qui utilise les résultats des deux premières phases pour la prédiction des efforts de coupe. La présente approche conduit à un modèle de prédiction des efforts de coupe 3D pour le processus de taillage et apparaît comme une alternative intéressante à l'approche classique de la littérature qui nécessite beaucoup d’essais expérimentaux pour déterminer les coefficients spécifiques de coupe caractéristique du matériau usiné. Nous avons également proposé une approche prédictive basée sur une modélisation analytique de l’interaction arête-copeau lors d’une opération de taillage en finition. La démarche proposée présente l'intérêt de s'affranchir des essais d'usinage, souvent longs et couteux, dans le cas de cette opération complexe (gabarit et géométrie des pièces, cinématique, formation de copeau, etc.). Enfin, le modèle proposé a été appliqué pour analyser le taillage des grandes couronnes (plusieurs mètres) en phase de finition / This work introduces a novel approach for a predictive model for hobbing process in order to improve the geometrical accuracy and quality of the manufactured part. An industrial case study of the generation of the teeth was simulated for prediction of effort. The calculation of the cutting forces is based on several steps: tool/part intersection step by means of a kinematic simulation of the process by CATIA, 2D numerical simulation of the process of the orthogonal cutting and finally the last step called ‘mechanistic simulation’ which uses the results of the other two steps for the prediction of cutting forces. This approach leads to model the 3D cutting force for hobbing process and appears as an interesting alternative to traditional mechanistic approach which requires a lot of experimental tests to determine the cutting force coefficients. Besides, we have proposed a predictive approach based on an analytical modeling of chip formation in finishing hobbing operation. The interest of the suggested approach is to be able to avoid machining tests in the case of this very complicated operation (huge dimensional parts, kinematic, chip formation process, etc...). Finally, the proposed model was applied to analyze the hobbing of larges parts (several meters) during finishing stage

Aus der Einleitung: "Faser-Kunststoff-Verbund (FKV)-Werkstoffe finden einen immer breiteren Einsatz in allen Bereichen der Industrie, wie zum Beispiel in der Luft- und Raumfahrt, im Automotive-Bereich, im Maschinenbau und bei Sportgeräten. Dabei entstehen besondere Herausforderungen für Entwickler, da Eigenschaften und Verfahren im Zusammenhang dieser Werkstoffe sich deutlich von denen der herkömmlich verwendeten Metalle oder unverstärkten Kunststoffe unterscheiden. Technische Fasern werden in verschiedenen Verarbeitungsformen und in Kombination mit vielfältigen Matrixsystemen angewendet. Ein Großteil der Fasern wird heutzutage in Form von multiaxialen Geweben oder Gelegen verarbeitet. Bei diesen Halbzeugen sind die Fasern in mehreren Lagen unterschiedlicher Ausrichtung übereinandergelegt. Metalle können damit sehr einfach durch leichtere Faser- Kunststoffverbunde ersetzt werden. Diese Technologien versuchen weitestgehend isotrope Bauteileigenschaften aus den eigentlich anisotropen Materialeigenschaften zu erzielen. Dies reizt jedoch das Potential der Werkstoffe nicht aus."

Today‘s customers expect zero defects with just-in-time (JIT) delivery from their suppliers, for the specified quantities, as a matter of standard practice. More importantly, customers expect companies to help them know what they need in terms of quantities and quality now, and for the future. No other change process adds long-term value as quickly as zero defects. Companies failing to embrace this quality culture face difficult challenges. To achieve this level of performance requires tremendous focus in an organisation and throughout its supply base. Business models around the world are changing dramatically from the "Source Local" to the "Source Anywhere and Build Anywhere" model (Cummins, 2008: 19). Companies have shifted away from a hierarchical, one-dimensional, supply chain entity to a fragmented network in favor of strategic partnerships with external entities. Many businesses facing such models are experiencing challenges and, if not managed correctly, can find themselves struggling to compete in this new landscape. Thus, when price concessions are so stringent, quality has to suffer. To reduce costs, suppliers are forced to seek less expensive ways to produce parts and components. Does this mean the use of different, less expensive materials? Does this mean less skilled labor? Does this mean production shortcuts? Or does this mean that suppliers just bite the bullet and pay the price? Once all the costs have been extracted from the supply chain, the only thing left to suffer is quality. The underlying objective of this research is to investigate the impact of delivery performance for a selected part at General Motors South Africa. In order to develop a research strategy to deal with, and solve, the main problem, the following research questions have been identified: a) What can be learned from literature about the impact of quality costs? b) Why is this specific part a suitable candidate for a cost investigation? c) What are the processes involved if a defect occurs? d) How can the cost be estimated? e) What effect does poor supplier quality have on productivity? This dissertation aims to investigate the problems and challenges General Motors South Africa are facing pertaining to the delivery performance of a selected part. The dissertation will also strive to highlight the impact of poor supplier quality on productivity and the related cost implications. Conclusions and recommendations will furthermore be outlined.

The thesis analyses the marketing strategy of IMOPRA s.r.o. company which operates in the sphere of automotive industry. The theoretical part is formed by the first free chapters and is elaborated from the standpoint of strategic marketing and strategic management. The other chapters form the analytical part which contains general characteristics of IMOPRA s.r.o. company and it analyses its existing marketing strategy from the standpoint of its specific position on B2B market as a certificated manufacturer of air conditioning parts. The conclusion contains the evaluation of company existing marketing strategy and it recommends some partial potential improvements.

Wave propagation problems can be modeled by partial differential equations. In this thesis, we study wave propagation in fluids and in solids, modeled by the acoustic wave equation and the elastic wave equation, respectively. In real-world applications, waves often propagate in heterogeneous media with complex geometries, which makes it impossible to derive exact solutions to the governing equations. Alternatively, we seek approximated solutions by constructing numerical methods and implementing on modern computers. An efficient numerical method produces accurate approximations at low computational cost. There are many choices of numerical methods for solving partial differential equations. Which method is more efficient than the others depends on the particular problem we consider. In this thesis, we study two numerical methods: the finite difference method and the discontinuous Galerkin method. The finite difference method is conceptually simple and easy to implement, but has difficulties in handling complex geometries of the computational domain. We construct high order finite difference methods for wave propagation in heterogeneous media with complex geometries. In addition, we derive error estimates to a class of finite difference operators applied to the acoustic wave equation. The discontinuous Galerkin method is flexible with complex geometries. Moreover, the discontinuous nature between elements makes the method suitable for multiphysics problems. We use an energy based discontinuous Galerkin method to solve a coupled acoustic-elastic problem.

Costs for repairing non-conforming parts may cause any company that is struggling with this problem, considerable damage. It is therefore essential that the problem was not relegated to the sidelines. The aim of this study was to find the cause of the large amount of non-conforming pieces and create a calculation of financial costs associated with the production of non-conforming parts and highlight the advantages of the individual methods of control depending on the size of the production of the four most problematic part. The first section summarizes the findings regarding the operational management-Industrial Engineering and Quality. A special chapter is devoted to the control systems in three foreign companies. The practical part deals with the resulting problem of non-conforming parts in Meopta-Optika, Ltd. and analyzes the situation through interviews, observation and application of mathematical and statistical methods to internal data. The outcome of the work will be recommendations that I could eliminate the problem.

Diploma thesis is analysing specific aspects of spare parts logistics on practical situation of Renault Česká Republika, a.s. ("RCR") and its largest concessionaire, RENAULT RETAIL GROUP CZ, s.r.o. (formerly Renault Praha Zličín - "RPZ"). Elements of spare parts supply chain are described separately with focus on spare parts distribution centre in Györ, Hungary, which is later compared with similar centres of Škoda Auto and Toyota. Furthermore the inbound logistics processes of RCR is described and commented. Subsequent parts of the thesis focus on the analysis of spare parts warehouse with objective to improve the efficiency of stored references compound in order to eliminate dispensable references which are being stored. This improvement should therefore allow ameliorated fixing of invested cash flow and minimise the amount of references to be ordered urgently due to unsuitable composition of stock in storage. Finally the thesis deals with effects impact of severe events such, in particular with actual effect of Japanese earthquake on spare parts supply chain and optional measures to be taken to diversify and/or minimise such risks.

The masters's thesis is focused on the Czech B2B market with car spare parts. First chapter explains theoretical marketing terms and methods that are later used in a practical part of the thesis. Second part of the master's thesis reflects current situation on automotive aftermarket. The reader will learn about subjects conducting business in the industry, about unions and trade associations that are entered by the subjects to protect their rights and interests. The chapter also includes block exemption that has legislatively changed rules of selling counterparts and of car repair. The third part describes Opel Spare Parts Programme, which was created to sell original spare parts Opel to independent services. Similar programmes of other car producers are compared in this chapter, and it also draws a comparison between offers of competitors in form of independent distributors of spare parts. B2B marketing research can be found at the end of the master's thesis, its aim was to identify levels of satisfaction with content and rules of the Opel Spare Parts Programme. Representatives of authorised Opel services became research respondents. Results of the research were used for planning marketing activities for 2013 schedule.

Wave phenomena appear in many fields of science such as acoustics, geophysics, and quantum mechanics. They can often be described by partial differential equations (PDEs). As PDEs typically are too difficult to solve by hand, the only option is to compute approximate solutions by implementing numerical methods on computers. Ideally, the numerical methods should produce accurate solutions at low computational cost. For wave propagation problems, high-order finite difference methods are known to be computationally cheap, but historically it has been difficult to construct stable methods. Thus, they have not been guaranteed to produce reasonable results. In this thesis we consider finite difference methods on summation-by-parts (SBP) form. To impose boundary and interface conditions we use the simultaneous approximation term (SAT) method. The SBP-SAT technique is designed such that the numerical solution mimics the energy estimates satisfied by the true solution. Hence, SBP-SAT schemes are energy-stable by construction and guaranteed to converge to the true solution of well-posed linear PDE. The SBP-SAT framework provides a means to derive high-order methods without jeopardizing stability. Thus, they overcome most of the drawbacks historically associated with finite difference methods. This thesis consists of three parts. The first part is devoted to improving existing SBP-SAT methods. In Papers I and II, we derive schemes with improved accuracy compared to standard schemes. In Paper III, we present an embedded boundary method that makes it easier to cope with complex geometries. The second part of the thesis shows how to apply the SBP-SAT method to wave propagation problems in acoustics (Paper IV) and quantum mechanics (Papers V and VI). The third part of the thesis, consisting of Paper VII, presents an efficient, fully explicit time-integration scheme well suited for locally refined meshes.