This research explores a hardware-based parallel simulation mechanism that can dramatically improve the speed of simulating flexible manufacturing systems (FMS) by applying appropriate enabling hardware technologies. The hardware-based parallel simulation refers to running a simulation on a multi-microprocessor integrated circuit board, called the simulator, which is specifically designed for the purpose of simulating a specific FMS. The board is composed of a collection of micro-emulators capable of mimicking the operation of equipment in FMS such as machining centers, transporters, and load/unload stations. To design possible architectures for the board, a mapping technology is applied by making use of the physical layout information of an FMS. Under such a mapping method, the simulation model is decomposed into a cluster of micro emulator on the board where each workstation is represented by one micro emulator. Three potential architectures for the proposed simulator, namely, the bus-based architecture, the shared-memory based architecture, and the parallel I/O port based architecture, are studied. To provide a suitable parallel computing platform, a prototype simulator based on the combination of the shared-memory and the parallel I/O port architecture is physically built. Besides the development of the hardware simulator, a time scaling simulation method is also developed for execution on the proposed simulator. The method uses the on-board digital clock to synchronize the parallel simulation being performed on different microprocessors. The advantage of the time scaling technology is that the sequence of simulation events is sorted naturally in consistent with the real events. In this way, no entangled waiting is needed as in the conservative parallel simulation methods so as to reduce the synchronization overhead and the danger of having deadlock. Experiments on the prototype simulator show that the time scaling simulation method, combined with the unique hardware features of the FMS specific simulator, achieves a large speedup compared to conventional software-based simulation methods. / Ph. D.

The thesis presents an approach to adaptive decision making strategies to reduce bottlenecks in a drilling operation and to extend tool life. It is an attempt to portray the real drilling system in a typical Flexible Manufacturing System (FMS) layout. The system designed serves as back end intelligence to drilling machines (INTELLIDRILL) in a Flexible Manufacturing System for making dynamic and real time decisions. INTELLIDRILL uses mathematical and adaptive tool reliability models to simulate the machining conditions and tool availability for an operation based on history of tool failures. The results are used to compute the machining parameters and the tools required for an operation. INTELLIDRILL can devise strategies for different tool materials to operate on batches of different materials. INTELLIDRILL decisions could lead to significant savings in tooling costs and reduction in flow line bottlenecks.

The thesis presents an approach to adaptive decision making strategies to reduce bottlenecks in a drilling operation and to extend tool life. It is an attempt to portray the real drilling system in a typical Flexible Manufacturing System (FMS) layout. The system designed serves as back end intelligence to drilling machines (INTELLIDRILL) in a Flexible Manufacturing System for making dynamic and real time decisions. INTELLIDRILL uses mathematical and adaptive tool reliability models to simulate the machining conditions and tool availability for an operation based on history of tool failures. The results are used to compute the machining parameters and the tools required for an operation. INTELLIDRILL can devise strategies for different tool materials to operate on batches of different materials. INTELLIDRILL decisions could lead to significant savings in tooling costs and reduction in flow line bottlenecks.

The aim of this paper is to identify the enablers, barriers and benefits of implementing reconfigurable jigs in the off-site manufacturing of unique house elements. Due to de- mands on customization, volume and lowering the cost, there is a need to increase flex- ibility in the industry. The paper focuses on mainly two phases of implementation, which are manufacturing, design and engineering. The research questions are answered by applying a single case study method, taking place in a Swedish house manufacturing company. The study consists of four different techniques – interviews, time study, observations, and questionnaire which are sup- ported with an additional literature review. Hence, research questions are answered from a triangulation approach providing nuanced and dynamic perspectives. From observations and time study it is concluded that in current situation, changeover in manufacturing is time-consuming due to the difference in complexity of product var- iants, along with a complex and inefficient setup process that is not responsive to a changeable environment. Findings imply that the barriers in both phases include lack of knowledge about reconfigurability, communication, current capabilities of CAD sys- tems as well as training and education. Enablers are found to be awareness of the needs of improvements, long-term mindset and working with product platforms. The benefits of implementing reconfigurable jigs include a reduction of setup time in manufacturing, better storage and sharing of information along with a better interpretation of that in- formation, a better structure in the organisation.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-02-15T15:42:38Z No. of bitstreams: 1 Vagner Gerhardt Mâncio_.pdf: 2330651 bytes, checksum: 51d1129f6c7064f70ea101a75bca32d1 (MD5) / Made available in DSpace on 2016-02-15T15:42:38Z (GMT). No. of bitstreams: 1 Vagner Gerhardt Mâncio_.pdf: 2330651 bytes, checksum: 51d1129f6c7064f70ea101a75bca32d1 (MD5) Previous issue date: 2015-07-03 / Nenhuma / A competição entre as empresas é cada vez mais um fator de sobrevivência, e a busca de diferenciais é o principal objetivo para que as empresas tornem-se destaques no mercado e se mantenham competitivas. Com o objetivo de contribuir para a evolução das empresas com variedade de produtos e uma taxa média de produção, desenvolveu-se esta pesquisa sobre a viabilidade de altos investimentos em automação e a criação de um método para a escolha de equipamentos a partir de uma visão estratégica, considerando as principais dimensões de competição: custo, qualidade, flexibilidade, entrega. A pesquisa delimita-se no campo de Sistemas Flexíveis de Manufatura – do inglês Flexible Manufacturing System (FMS) –, cujas análises estratégicas e de equipamentos de automatização tenham características de sistemas flexíveis. A pesquisa foi desenvolvida na metodologia de modelagem quali-quantitativa, na qual, através da modelagem dos cenários, puderam ser realizadas avaliações qualitativas e quantitativas; o Método de Análise Hierárquica – do inglês Analytic Hierarchy Process (AHP) – foi utilizado para determinar o cenário que melhor combina com a principal variável competitiva. Para o desenvolvimento da pesquisa, foram coletadas opiniões de especialistas de empresas sobre os pesos comparativos do método AHP e sobre os equipamentos de automação que fazem parte dos cenários criados. O cenário 1 possui layout escada com a movimentação dos materiais realizado por esteiras através de pallets, cuja manipulação é realizada por sistemas pneumáticos. O cenário 2 possui layout campo aberto com a movimentação dos materiais realizado por veículos guiados automaticamente – do inglês Automated Guided Vehicle (AGV), capazes de abastecer e descarregar os equipamentos. O cenário 3 possui layout centrado no robô, com 3 robôs que se movimentam em uma esteira para abastecer e desabastecer os equipamentos. Foram propostos dois métodos de cálculo do mérito final dos cenários, e, para ambos, o melhor cenário foi o 3. Adicionalmente, concluiu-se que adotar o cenário 3 é melhor do que não fazer nada, ou seja, continuar com a instalação atual da célula estudada. / The competition between companies is increasingly a factor of survival, and the search for differential is the main objective for companies to become highlights in the market and remain competitive. In order to contribute to the development of companies with a variety of products and an average rate of production, this research was carried out on the feasibility of large investments in automation and the creation of a method for choosing equipment from a vision strategic, considering the main dimensions of competition: cost, quality, flexibility, delivery. The research is delimited in the Flexible Manufacturing Systems field (FMS) whose strategic analysis and automation equipment have flexible systems characteristics. The research was conducted in the qualitative and quantitative modeling methodology, in which, through the modeling of scenarios, could be carried out qualitative and quantitative assessments; the Analytic Hierarchy Process (AHP) was used to determine the setting that best suits the key competitive variable. For the development of research, business expert opinions were collected on the comparative weights of AHP and on the automation equipment that are part of the created scenarios. Scenario 1 has ladder layout with the movement of the materials carried by pallets through mats, in which the handling of materials is achieved by pneumatic systems. Scenario 2 has the open layout with the movement of materials held by Automated Guided Vehicle (AGV), able to supply and unloading equipment. Scenario 3 has focused on the layout robot, in which there are three robots, moving on a conveyor and load and unload the equipment. Two methods of calculating the final merit of the scenarios were proposed. By both methods, the best scenario was the 3. Additionally, the conclusion is that adopting the scenario 3 is better than doing nothing, that is, continue with the current installation of cell studied.

To improve product quality and reduce cost, batch production is often implemented in many exible manufacturing systems. However, the current literature does not provide any method to analyze the quality performance in a flexible manufacturing system with batch production. In this research, we present an analytical method with closed-form formula to evaluate the quality performance in such systems. Based on the model, we discover and investigate monotonic and non-monotonic properties in quality to provide practical guidance for operation management. To improve product quality, we introduce the notions of quality improvability with respect to product sequencing. In addition, we develop the indicators for quality improvability based on the data available on the factory floor rather than complicated calculations. We define the bottleneck sequence and bottleneck transition as the ones that impede quality in the strongest manner, investigate the sensitivity of quality performance with respect to sequences and transitions, and propose quality bottleneck sequence and transition indicators based on the measured data. Finally, we provide a case study at an automotive paint shop to show how this method is applied to improve paint quality. Moreover, we explore a potential application to reduce energy consumption and atmospheric emissions at automotive paint shops. By selecting appropriate batch and sequence policies, the paint quality can be improved and repaints can be reduced so that less material and energy will be consumed, and less atmospheric emissions will be generated. It is shown that such scheduling and control method can lead to significant energy savings and emission reduction with no extra investment nor changes to existing painting processes. The successful development of such method would open up a new area in manufacturing systems research and contribute to establish a solid foundation for an integrated study on productivity, quality and exibility. In addition, it will provide production engineers and operation managers a quantitative tool for continuous improvement on product quality in flexible manufacturing environment

No description available.

A necessidade de aumento de produção, da redução de custos e do aumento da qualidade de bens de consumo, tem motivado a constante evolução dos sistemas de produção, migrando os tradicionais sistemas de produção para os modernos e complexos sistemas de manufatura, onde a performance depende da eficiência dos equipamentos e do controle do processo. Por outro lado, a eficiência dos equipamentos depende de sua confiabilidade e manutenabilidade. Neste trabalho a análise de performance é avaliada com o uso de Rede de Petri p-t-Temporizada e através de simulações, incluindo a avaliação da confiabilidade do processo pela análise da otimização da saída do sistema, isto é, quantidade de itens produzidos. Nesta abordagem, uma lógica linear foi desenvolvida e validada utilizando-se uma comparação de resultados das classes de estados do algoritmo proposto com a ferramenta de simulação Tina para um modelo de um esquema produtor consumidor. Apresenta-se um estudo de caso na indústria automotiva, consistindo na análise dos problemas reais enfrentados em uma fábrica de carrocerias, com o uso da Rede de Petri p-t-Temporizada. / The necessity of growing in production, with reduction of costs and improvement in the quality of consumption good, has motivated the constant evolution of production systems, transforming traditional production systems into the modern and complex manufacturing systems, where the performance depends on the efficiency of the equipment and process control. On the other hand, the equipment efficiency depends of their reliability and maintainability. In this work it is proposed a performance evaluation and analysis with the use of p-t- Timed Petri Nets using simulations, including process reliability analysis of the system through the throughput optimization, i.e., produced amount of goods. In this approach, a linear logic statement was developed and validated using a comparison of results of classes of states between the Tina simulation environment and the algorithm considered for a model of a producing consuming system. A case study in the automotive industry is presented, consisting of the analysis of the real problems found in a body shop plant, with the use of Timed Petri Net.

The difficulties in responding to variation in product order mixes and load levels effectively in make to order are known. Most of the existing approaches consider releasing jobs to the shop (input control), changing capacity levels (output control) in a controlled way, order acceptance with different definitions of work load and due date assignment. Controlling the processes, routing options and the order accepting capacity with various tool combinations that will decrease tool loading are not considered properly. However the manufacturing flexibility provided by the computer numerically controlled (CNC) machines, provides both part variety and due date achievement given a reasonable extra capacity. Positive effects of flexibility on the due date achievement of the make to order is shown with a variety of experimental and field studies leaving little doubt. However taking flexibility only as a strategic issue and not considering it as a means of planning and management in either the short term or medium term decisions have been commonplace practice. In this study, benefits of providing three kinds of flexibility, considering order pool and acceptance probability of the new arrivals in a periodic setting, is the focal issue. If the required flexible environment is provided, the necessity to make a detailed job loading, route planning and scheduling will be reduced to a low level and a high shop congestion and due date achievement will be realized simultaneously. A typical realistic shop with a scaled part mix is assumed in the flexibility management modeling and simulation experiments are conducted applying periodical flexibility planning approach. These experiments briefly support the ideas that worth of anticipation is more than plain expectations and flexibility improves robustness.

A necessidade de aumento de produção, da redução de custos e do aumento da qualidade de bens de consumo, tem motivado a constante evolução dos sistemas de produção, migrando os tradicionais sistemas de produção para os modernos e complexos sistemas de manufatura, onde a performance depende da eficiência dos equipamentos e do controle do processo. Por outro lado, a eficiência dos equipamentos depende de sua confiabilidade e manutenabilidade. Neste trabalho a análise de performance é avaliada com o uso de Rede de Petri p-t-Temporizada e através de simulações, incluindo a avaliação da confiabilidade do processo pela análise da otimização da saída do sistema, isto é, quantidade de itens produzidos. Nesta abordagem, uma lógica linear foi desenvolvida e validada utilizando-se uma comparação de resultados das classes de estados do algoritmo proposto com a ferramenta de simulação Tina para um modelo de um esquema produtor consumidor. Apresenta-se um estudo de caso na indústria automotiva, consistindo na análise dos problemas reais enfrentados em uma fábrica de carrocerias, com o uso da Rede de Petri p-t-Temporizada. / The necessity of growing in production, with reduction of costs and improvement in the quality of consumption good, has motivated the constant evolution of production systems, transforming traditional production systems into the modern and complex manufacturing systems, where the performance depends on the efficiency of the equipment and process control. On the other hand, the equipment efficiency depends of their reliability and maintainability. In this work it is proposed a performance evaluation and analysis with the use of p-t- Timed Petri Nets using simulations, including process reliability analysis of the system through the throughput optimization, i.e., produced amount of goods. In this approach, a linear logic statement was developed and validated using a comparison of results of classes of states between the Tina simulation environment and the algorithm considered for a model of a producing consuming system. A case study in the automotive industry is presented, consisting of the analysis of the real problems found in a body shop plant, with the use of Timed Petri Net.