Simulação aplicada a manufatura flexivel

Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro TecnologicoOs sistemas flexíveis de manufatura resultam do desejo de alcançar a produtividade da produção de massa com a agilidade da fabricação por encomenda. Em virtude do grau de automação, da flexibilidade, do número elevado de diferentes produtos fabricados em pequenos lotes, estes sistemas apresentam uma complexidade maior do que os tradicionais. A obtenção da eficiência produtiva destes sistemas envolve otimizar um grande número de variáveis decisórias e solucionar uma problemática variada que vai de problemas de longo prazo, como os de projeto, médio prazo, representado pelo planejamento, curto prazo, identificado pelos problemas de programação e, ainda, por problemas de curtíssimo prazo, relacionados com o controle em tempo-real do sistema. A complexidade destes sistemas fez da simulação senão a única ferramenta para sua análise, pelo menos, a mais importante. Com o barateamento dos custos de hardware e a crescente aceitação da simulação como técnica da solução de problemas, o número de recursos de software relacionados aos SFM cresceu muito além do que qualquer um seria capaz de acompanhar. O propósito deste trabalho é descrever estes sistemas, sua origem, vantagens e problemática, classificando e analisando os instrumentos de software disponíveis possibilitando, desta forma, decisões melhores e mais rápidas por parte de quem pretenda faser uso da simulação para estudá-los

Integrated knowledge-based hierarchical modelling of manufacturing organizations

The objective of this thesis is to research into an integrated knowledge-based simulation method, which combines the capability of knowledge based simulation and a structured analysis method, for the design and analysis of complex and hierarchical manufacturing organizations. This means manufacturing organizations analysed according to this methodology can manage the tactical and operational planning as well as the direct operation of shop floor. [Continues.

Development of a standard framework for manufacturing simulators

Discrete event simulation is now a well established modelling and experimental technique for the analysis of manufacturing systems. Since it was first employed as a technique, much of the research and commercial developments in the field have been concerned with improving the considerable task of model specification in order to improve productivity and reduce the level of modelling and programming expertise required. The main areas of research have been the development of modelling structures to bring modularity in program development, incorporating such structures in simulation software systems which would alleviate some of the programming burden, and the use of automatic programming systems to develop interfaces that would raise the model specification to a higher level of abstraction. A more recent development in the field has been the advent of a new generation of software, often referred to as manufacturing simulators, which have incorporated extensive manufacturing system domain knowledge in the model specification interface. Many manufacturing simulators are now commercially available, but their development has not been based on any common standard. This is evident in the differences that exist between their interfaces, internal data representation methods and modelling capabilities. The lack of a standard makes it impossible to reuse any part of a model when a user finds it necessary to move from one simulator to another. In such cases, not only a new modelling language has to be learnt but also the complete model has to be developed again requiring considerable time and effort. The motivation for the research was the need for the development of a standard that is necessary to improve reusability of models and is the first step towards interchangability of such models. A standard framework for manufacturing simulators has been developed. It consists of a data model that is independent of any simulator, and a translation module for converting model specification data into the internal data representation of manufacturing simulators; the translators are application specific, but the methodology is common and illustrated for three popular simulators. The data model provides for a minimum common model data specification which is based on an extensive analysis of existing simulators. It uses dialogues for interface and the frame knowledge representation method for modular storage of data. The translation methodology uses production rules for data mapping