Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (p. 147-154).

Com o aumento da competição, provocado pela globalização da economia, as organizações estão em uma luta contínua pela sua sobrevivência no mercado. Essa sobrevivência passa obrigatoriamente pela organização de sua gestão, em busca de tornar-se mais competitiva. Um dos pontos principais que fazem as empresas mais competitivas é a gestão de seus processos e o alinhamento deles com seus objetivos estratégicos. A eficiência das empresas está ligada diretamente à eficiência de seus processos, de forma que seu aperfeiçoamento é um dos objetivos fundamentais para qualquer empresa, sendo o tema central deste trabalho. Inicialmente é apresentada uma série de conceitos que demonstram a importância da gestão de processos, detalhando algumas das ferramentas de desenho e notações utilizadas. A seguir, são apresentadas algumas das principais metodologias utilizadas atualmente para o mapeamento de processos, e um quadro comparativo dessas metodologias é elaborado e analisado, verificando-se as principais etapas de cada metodologia e seu principal objetivo. Posteriormente, é feita a proposição de uma nova metodologia de mapeamento de processos, que tem como princípio a implantação de melhorias na medida em que elas são detectadas durante o mapeamento, fazendo com que as empresas obtenham resultados mais rápidos. A metodologia proposta difere fundamentalmente das metodologias usuais pelo fato destas só implementarem as melhorias depois de realizado todo o processo de mapeamento, o que torna a obtenção de resultados muito demorada. / With the increase of competition, caused by the economy globalization, the organizations are in a continuous struggle for their survival in the market. This survival necessarily passes by the organization of its management, aiming to become more competitive. One of the main points that make the companies more competitive is the management of their processes and their alignment with their strategic goals. The efficiency of the companies is directly connected to the efficiency of their processes, so that its improvement is one of the fundamental goals for any company, that being the central theme of this paper. Initially, a series of concepts that show the importance of the process management is introduced, detailing some of the drawing tools and used notations. Following, some of the main methodologies currently used for the process mapping are presented, and a comparative table of theses methodologies is elaborated and analyzed, verifying the main steps of each one and their main goal. Subsequently, the proposition of a new methodology for process mapping is made, whose principle is the implantation of improvement as they are detected during the mapping, leading the companies to obtain faster results. The proposed methodology essentially differs from the usual methodologies because these ones just implement the improvements after all the mapping process is made, which takes a long time for the achievement of results.

Com o aumento da competição, provocado pela globalização da economia, as organizações estão em uma luta contínua pela sua sobrevivência no mercado. Essa sobrevivência passa obrigatoriamente pela organização de sua gestão, em busca de tornar-se mais competitiva. Um dos pontos principais que fazem as empresas mais competitivas é a gestão de seus processos e o alinhamento deles com seus objetivos estratégicos. A eficiência das empresas está ligada diretamente à eficiência de seus processos, de forma que seu aperfeiçoamento é um dos objetivos fundamentais para qualquer empresa, sendo o tema central deste trabalho. Inicialmente é apresentada uma série de conceitos que demonstram a importância da gestão de processos, detalhando algumas das ferramentas de desenho e notações utilizadas. A seguir, são apresentadas algumas das principais metodologias utilizadas atualmente para o mapeamento de processos, e um quadro comparativo dessas metodologias é elaborado e analisado, verificando-se as principais etapas de cada metodologia e seu principal objetivo. Posteriormente, é feita a proposição de uma nova metodologia de mapeamento de processos, que tem como princípio a implantação de melhorias na medida em que elas são detectadas durante o mapeamento, fazendo com que as empresas obtenham resultados mais rápidos. A metodologia proposta difere fundamentalmente das metodologias usuais pelo fato destas só implementarem as melhorias depois de realizado todo o processo de mapeamento, o que torna a obtenção de resultados muito demorada. / With the increase of competition, caused by the economy globalization, the organizations are in a continuous struggle for their survival in the market. This survival necessarily passes by the organization of its management, aiming to become more competitive. One of the main points that make the companies more competitive is the management of their processes and their alignment with their strategic goals. The efficiency of the companies is directly connected to the efficiency of their processes, so that its improvement is one of the fundamental goals for any company, that being the central theme of this paper. Initially, a series of concepts that show the importance of the process management is introduced, detailing some of the drawing tools and used notations. Following, some of the main methodologies currently used for the process mapping are presented, and a comparative table of theses methodologies is elaborated and analyzed, verifying the main steps of each one and their main goal. Subsequently, the proposition of a new methodology for process mapping is made, whose principle is the implantation of improvement as they are detected during the mapping, leading the companies to obtain faster results. The proposed methodology essentially differs from the usual methodologies because these ones just implement the improvements after all the mapping process is made, which takes a long time for the achievement of results.

This work stems directly from a manufacturing company's need to improve the quality of its product and increase competitiveness in an industry where a physical understanding of its production process, known as centrifugal spinning, is lacking. Centrifugal spinning is the principal method of producing mineral wool; a product that is predominantly used for thermal and acoustic insulation. The production technique generates wool fibres from a molten jet that is directed to impinge onto four rotating wheels. However, it sometimes, and quite often produces mineral wool fibres of poor quality due to the presence of nonfibrous material or shots; a problem that has so far received little attention. This inquiry was undertaken with a VIew to providing insights into the physical mechanisms governing the formation of fibres and shots. Theoretical analyses and an experiment were conducted to investigate the important non-dimensional groups that govern fibre and shot formation, but concentrating mainly on understanding the mechanics of shot formation. It was established that fibres are formed from the break-up of the thin layer around the rotating wheels. It was also established that shots are formed from droplets produced as a result of jet splashing. Jet splashing is temperature independent since it occurs in a short time-scale from jet impingement with little melt cooling; it is largely governed by force balance and geometrical parameters. Such an observation led to an impinging water jet experiment that was conducted at ambient temperature and its image processed by computer software. From this, it was determined that the significant non-dimensional group that governs jet splashing on a rotating wheel or drum was that due to the jet impact position. The least liquid splashing was found to occur when the jet impinged in the forward position (relative to the direction of rotation) because the depth of fluid underneath the impingement position was always at its minimum. The speed of drum rotation affected jet splashing only up to a critical value, beyond which it had little influence.

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This thesis reports upon a second phase of research into the effects of free-stream turbulence quantities on heat transfer to impermeable gas turbine blading. It describes the development of a novel form of turbulence generator, to control separately the turbulence quantities intensity and frequency upstream of a cascade of blades at levels typical of the gas turbine. The turbulence generator was calibrated for these individual quantities, with a hotfilament anemometer system combined with on-line analog and digital signal processing. Blade heat transfer coefficients measured by two independent techniques are compared. A large quantity of data is presented, taken from a first stage high pressure rotor blade and a nozzle guide vane. These were subjected to steady flow and turbulent streams induced by both the novel turbulence generator and by more conventional turbulence grids. Surface pressure measurements have also been made, to predict the heat transfer rates by applying formulae derived from simple geometries. Much of the boundary layer over the two blades was apparently laminar. For the laminar regions, the simple formulae for heat transfer (flat plate for example) multiplied by a turbulence term, will provide as good a correlation as any. The intensity Tu is the most important turbulence quantity, but there is some evidence that the frequency of the perturbations can effect heat transfer. Other evidence presented would s'uggest that profile geometry is an overriding factor, which dictates the development of the turbulence, whatever its origin, as well as controlling its interaction with the boundary layer. None of the correlations available for the prediction of boundary layer transition are applicable. On both blade suction surfaces separation seems to have occurred, and the analysis indicates that transition on the pressure surfaces of modern blades will be inhibited by the high free-stream accelerations. Beyond transition, heat transfer is little affected by turbulence. It is now clear, that measurements of the turbulence as it develops through the cascade must be performed before a successful prediction procedure for all of the boundary layer regions can emerge.

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