Processos de montagem em geral necessitam de instruções para serem executados, desde a montagem de simples brinquedos até máquinas complexas. Tradicionalmente, essas instruções vem na forma de manuais em papel ou meio digital. Seja qual for o modo, os manuais de instruções utilizam desenhos, diagramas ou fotos, além de instruções textuais para indicar a sequência de montagem do início até o estado final. Procurando mudar esse paradigma, esse trabalho propõe um sistema para auxílio à montagem que utiliza realidade aumentada para guiar o usuário no processo. Através de processamento de imagens capturadas por uma câmera o sistema reconhece cada peça e por meio de sinais gráficos é indicado ao usuário qual a peça a ser manipulada e onde deve ser posicionada. Em seguida é feito a verificação do posicionamento das peças e o usuário é alertado quando a tarefa de montagem atinge o estado final. Muitos trabalhos na área utilizam algum tipo de dispositivo customizado como \"head mounted display\" (HMD) e marcadores para auxiliar o rastreamento da câmera e identificação das peças, limitando a popularização dessa tecnologia. Tendo esse último ponto em vista, propõe-se um sistema que não utiliza qualquer dispositivo customizado ou marcadores para rastreamento. Além disso, todos os processos do sistema são executados em software embarcado, não necessitando de comunicação com outros computadores para o processamento de imagens. Como o sistema não faz uso de marcadores para a identificação das peças, inicialmente é proposto a implementação do sistema para guiar o usuário na resolução de um quebra-cabeças plano. O sistema proposto é denominado como MARA (Montagem Assistida por Realidade Aumentada). / Assembly processes for simple toys or complex machines usually requires instructions to be executed. Traditionally, these instructions are written in the form of paper or digital manuals. These manuals contains descriptive text, photos or diagrams to guide the assembly sequence from the beginning to the final state. To change this paradigm, it is proposed in this work an augmented reality system to guide assembly tasks. The system recognizes each assembly piece through image processing techniques and guides the piece placement with graphic signals. Later, the system checks if the pieces are properly assembled and warns the user when the assembly have been finished. In the field of assembly assisted by augmented reality systems, many works use some kind of customized device, like head mounted displays (HMD). Furthermore, markers have been used to track camera position and identify assembly parts. These two features restrict the spread of the technology, thus in the proposed work customized devices and markers to track and identify parts shall not be used. Besides, all the processing are executed on embedded software without the need of communication with other computers to help image processing. The first implementation of the proposed system assists the user on the assembly of a planar puzzle, as the proposed system do not use markers to recognize assembly pieces. This system is being called A3R (Assembly Assisted by Augmented Reality).

Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Systems Science and Industrial Engineering Department, 2006. / Includes bibliographical references.

Assembly line balancing problem is one of the most studied NP-Hard problems. NP-Hardness leads us to search for a good solution instead of the optimal solution especially for the big-size problems. Meta-heuristic algorithms are the search methods which are developed to find good solutions to the big-size and combinatorial problems. In this study, it is aimed at solving the multi-objective multi-model assembly line balancing problem of a company. A meta-heuristic algorithm is developed to solve the deterministic assembly line balancing problems. The algorithm developed is tested using the test problems in the literature and the the real life problem of the company as well. The results are analyzed and found to be promising and a solution is proposed for the firm.

Purpose - The purpose of the bachelor thesis is to describe the relationship between Third-party logistics (3PL) suppliers and car assemblers under Just-in-sequence (JIS). The paper refers to a case in the Spanish automotive industry and the main target is to identify and analyse the potential problems between both parts and explain how they work together. Methodology – The paper is based on a case study research, with the aid of interviews with people of the industry and participant-observations, to explain how this part of the supply chain works, the relationships along the chain and the difficulties of sequencing. Results – The paper identifies and analyses the potential problems between both parts and relates how a mistake from one of them can affect the other one. Then, the results are discussed and associated with some concepts of the theoretical framework. Limitations - The results of this case study can only be related to the Spanish automotive industry, for car assemblers that work under a JIS context with several 3PL suppliers. The case study only identifies and analyses the problems, solutions and measures for managing them are not provided.

Purpose – The purpose with this study is to investigate how an assembly line for products with long cycle time, high product variation and operators who follow the products through the flow can be planned for a high resource utilization as well as the challenges that can arise when planning an assembly line with an increasing demand and how these can be handled. Method – To fulfill the purpose of this study a case study was conducted at Mastec Components AB in Vaggeryd. The empirical data gathered from the case study was obtained through interviews, observations and document studies. The empirical data was then analysed against theory, which means that pattern matching was used and the analyse led to the studies results. Findings – This study illustrates how an assembly line with special demands can be planned to gain high resource utilization. When the products cycle times are multiple they can be sorted into product families to simplify the planning and it also enables a tacted planning method to be used. The study also presents how the usage of time buffers can facilitate the planning of an assembly line. Moreover the study illuminates the importance of controlling tact, both from the customer and the own production. When demand increases it is important that the production line is capable to keep up, therefore some arrangements can be done to reduce waste and increase capacity. Possible alternatives can be buffers, allocating resources and parallel assembly lines. Implications – The study investigates a type of assembly line where the operators follow the products through the flow. This type of assembly line is unexplored in theory and thereby a knowledge gap has been identified which partly have been covered by this study. Further on, the study contributed to an increased understanding of the consequences that occur when operators follow the flow and when products have long varying cycle times. The study also shows the value of calculating tact and use the advantages from it to easier handle variation in demand. Limitations – The case study was performed as one case study which means that only one unit has been analysed. This was due to the lack of resources to do several case studies, both regarding time and ability to find more facilities with similar conditions. If it were possible to conduct more case studies the results could have been more general. Keywords – Tact, tact time, tacted planning, assembly line, planning, operators, buffer.

Low-voltage switchgear and controlgear assemblies with a rated short-circuit withstand strength above 10 kA, are required, by law, to conform to the South African standard, SANS 1473-1 (Low Voltage Switchgear and Controlgear Assemblies: Part 1: Typetested, partially type-tested and specially tested assemblies with rated short-circuit withstand strength above lOkA). Standard SANS 1473-1 stipulates three categories of assemblies i.e. type-tested, partially type-tested and specially tested assemblies. The specially tested assembly is unique to the South African market, while the other two categories are stipulated in standard SANS IEC 60439-1 (Low Voltage Switchgear and Controlgear Assemblies: Part 1: Type-tested and partially type-tested assemblies), which is internationally accepted in many countries as the applicable low-voltage assembly standard. Standard SANS 1473-1 specifies seven type-tests for certification as a type-tested assembly (TTA), but specifies, at most, three type-tests for certification as a specially tested assembly (STA). The underlying purpose of a technical standard is to provide for the safety of people and property, with the purpose of the research being twofold: 1. To investigate if the testing requirements specified for a specially tested assembly (STA), in accordance with standard SANS 1473-1, are correctly applied, and do not pose any safety risks. 2. To investigate any safety risks that stem from the fact that four type-tests are excluded for verification as a specially tested assembly (STA), as opposed to the seven type tests required for verification as a type-tested assembly (TTA). The document highlights the technical inadequacies of an assembly that is certified as a STA, in accordance with standard SANS 1473-1, and the potential safety risks associated with this type of assembly classification. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2004.

Software systems have experienced an impressive growth in the last few decades and have impacted a wide variety of areas. In this respect, two elds bene t greatly. Learning and research. In this work, we present several software systems that we have created to assist in the process of learning and to help researchers by performing complex computations and generating data. We demonstrate three web-based educational video games that we developed to teach science to middle school students. We also describe several software systems that we created for research in graph theory and model checking. Finally, we discuss our results, contributions and future directions. / Educational perspectives -- Graph algorithms and their applications -- E-learning -- Model checking. / Educational perspectives -- Graph algorithms and their applications -- E-learning -- Model checking. / Department of Computer Science

In this study, we consider single model deterministic Assembly Line Balancing problem with task paralleling. The objective is to minimize the total cost which is composed of station opening cost and task dependent equipment cost. A branch and bound algorithm that allows two-level task paralleling is proposed. A heuristic algorithm is also developed both for obtaining efficient upper bounds to branch and bound and for achieving good approximate solutions for large sized problems. Computational experiments are conducted to investigate the effects of experimental parameters on the cost-related and algorithm-related performance measures. The exact algorithm results are compared to the proposed heuristic algorithm results, station paralleling results and optimal solutions without paralleling.

The increasing globalization of the market has rendered the competitive situation for companies worldwide more fierce than ever with order winners becoming order qualifiers and the demand continues to rise. Especially, the situation has become more complex for SME´s that are suppliers to large global companies. To ensure themselves that the suppliers are conforming to the high standards set by the large companies. In mediating the quality of the production as well as having a well-performing production, practitioners are using the term industrial look and feel to encapsulate a production that both deliver and looks the part. However, this term is loosely used, and a clear definition of it is missing, hence creating problems when the term industrial look and feel is used in production line design. In this study, the authors aim to investigate the possibilities of providing a clear definition of the term industrial look and feel and what it involves. Further, the authors want to investigate what are the important aspects to consider when designing a production line considering industrial look and feel. The study was directed by these three research questions: * How can Industrial Look and Feel be defined? * How does Industrial Look and Feel contribute to increased performance of a production line? * What is important to consider when designing a production line considering industrial look and feel in an HMLV environment? To answer the research questions a case study has been conducted at a company producing the robust data communication equipment and a literature review was conducted with the aim of understanding the concepts included in the term industrial look and feel. The study resulted in a definition of industrial look and feel, how industrial look and feel may contribute the production performance and important aspect to consider and include in the design of a production line considering industrial look and feel. Taking the newly defined concept of industrial look and feel into consideration, a concept assembly line was developed at the case study company.

A diferença entre estações de trabalho é considerada desprezível em linhas de montagem tradicionais. Por outro lado, linhas de montagem heterogêneas consideram o problema de indústrias nas quais os tempos das tarefas variam de acordo com alguma característica a ser selecionada para a tarefa. No Problema de Balanceamento e Atribuição de Trabalhadores em Linhas de Montagem (do inglês Assembly Line Worker Assignment and Balancing Problem, ALWABP), os trabalhadores são responsáveis por estações de trabalho e de acordo com as suas habilidades, eles executam as tarefas em diferentes quantidades de tempo. Em alguns casos, os trabalhadores podem até ser incapazes de executar algumas tarefas. No Problema de Balanceamento de Linhas de Montagem Robóticas (do inglês Robotic Assembly Line Balancing Problem, RALBP), há diferentes tipos de robôs e o conjunto de tarefas de cada estação deve ser executada por um robô. Robôs do mesmo tipo podem ser usados múltiplas vezes. Nós propomos métodos exatos e heurísticos para a minimização do tempo de ciclo destes dois problemas, para um número fixo de estações. Os problemas têm características similares que são exploradas para produzir limitantes inferiores, métodos inferiores, models de programação inteira mista, e regras de redução e dominância. Para a estratégia de ramificação do método de branch-and-bound, entretanto, as diferenças entre os problemas forçam o uso de dois algoritmos diferentes. Uma estratégia orientada a tarefas tem os melhores resultados para o ALWABP-2, enquanto uma estratégia orientada a estações tem os melhores resultados para o RALBP-2. Nós mostramos que os limitantes inferiores, heurísticas, modelos de programação inteira mista e algoritmos de branch-and-bound para estes dois problemas são competitivos com os métodos do estado da arte da literatura. / The difference among workstations is assumed to be negligible in traditional assembly lines. Heterogeneous assembly lines consider the problem of industries in which the task times vary according to some property to be selected for the task. In the Assembly Line Worker Assignment and Balancing Problem (ALWABP), workers are assigned to workstations and according to their abilities, they execute tasks in different amounts of time. In some cases they can even be incapable of executing some tasks. In the Robotic Assembly Line Balancing Problem (RALBP) there are different types of robots and each station must be executed by a robot. Multiple robots of the same type may be used. We propose exact and heuristic methods for minimizing the cycle time of these two problems, for a fixed number of stations. The problems have similar characteristics that are explored to produce lower bounds, heuristic methods, mixed-integer programming models, and reduction and dominance rules. For the branching strategy of the branch-and-bound method, however, the differences among the problem force the use of two different algorithms. A task-oriented strategy has the best results for the ALWABP-2 while a station-oriented strategy has the best results for the RALBP-2. The lower bounds, heuristics, MIP models and branch-and-bound algorithms for these two problems are shown to be competitive with the state-of-the-art methods in the literature.