A sobrevivência das organizações em cenários altamente competitivos tem exigido a melhoria da eficiência, flexibilidade e qualidade dos sistemas de produção (DE RON, 1998). Neste âmbito, a programação de tarefas assume grande responsabilidade ao suportar o planejamento e controle da manufatura, garantindo que estes processos estejam alinhados com os objetivos estratégicos das organizações. Esta dissertação aborda a programação de tarefas em sistemas de pintura com tempos de setup dependentes da sequência do processamento. No primeiro artigo é proposta uma sistemática para liberação do tamanho de lote que minimiza a soma dos custos de setup e pintura. Na sequência, os lotes liberados são sequenciados utilizando as regras Apparent Tardiness Cost (ATC) e Apparent Tardiness Cost with Setups (ATCS). Quando aplicado em processo de pintura, o ganho de eficiência da instalação medido através do Overall Equipment Effectiveness (OEE) foi de 32,84%. O segundo artigo propõe uma modificação na regra ATCS através da inclusão de um parâmetro relativo à qualidade de execução do procedimento de pintura. Tal parâmetro é justificado pelo impacto decorrente de falhas no processo de pintura, gerando atrasos de entrega. Esta nova heurística, quando aplicada no mesmo processo de pintura, elevou o OEE em 2,74%, a precisão de entrega em 2,11% e o percentual de embalagens completas ao final do processo de pintura em 8%. / The competitive industrial scenarios required companies to improve efficiency, flexibility and quality of production systems (RON, 1998). In this context, job scheduling is deemed important to support planning and control of manufacturing systems. This dissertation addresses the scheduling problem in painting systems where setups depend on the job sequence. The first paper proposes an approach to release batches aimed at minimizing the sum of setup and painting costs. The released lots are scheduled using the Apparent Tardiness Cost (ATC) and Apparent Tardiness Cost with Setups (ATCS) rules. When applied to a painting process, the proposed approach increased efficiency measured by the Overall Equipment Effectiveness 32.84%. The second article proposes a modification to the ATCS rule by including a quality related parameter. This parameter is tailored to reduce delivery delays due to quality problems. This new heuristic, when applied to the same painting process, increased the OEE 2.74%, the delivery accuracy 2.11% and the percentage of completed packages at the end of the painting process 8%.

A concorrência nos mercados mundiais impõe a necessidade de aumento da competitividade das empresas que desejam assumir posições de liderança nos segmentos em que atuam. Neste ínterim, a programação de tarefas contribui para que as empresas promovam a eficiente utilização dos recursos produtivos visando a realização de seus objetivos estratégicos. Esta dissertação enfoca a programação de tarefas em máquinas paralelas não-relacionadas e com tempos de setup dependentes da sequência de processamento. Primeiramente é abordado o objetivo de minimização do atraso total e do tempo total para a conclusão de um conjunto de tarefas, através de uma heurística de três etapas que (i) ordena as tarefas pelo WSPT (Weighted Shortest Processing Time), (ii) aloca as tarefas às máquinas e (iii) aprimora a solução proposta pela etapa (ii) através de Tabu Search. Quando aplicada em um ambiente de manufatura real composto por duas máquinas paralelas não-relacionadas no processo de metalização de filmes plásticos em alto vácuo, a heurística resulta em um desvio de 1,1% para o tempo total de processamento das tarefas e 4,6% para o atraso total, em comparação ao resultado ótimo obtido por enumeração. Na sequência, o objetivo passa a ser a minimização simultânea do atraso e do adiantamento das tarefas através de uma heurística de três etapas que (i) caracteriza o conjunto de tarefas por um conjunto de métricas, (ii) aloca as tarefas às máquinas através de uma versão modificada do ATCS (Apparent Tardiness Cost with Setup) de Lee e Pinedo (1997), e (iii) aprimora a solução final com Tabu Search. A aplicação em dados reais resulta em 14% de desvio em relação à solução ótima obtida por enumeração. Quando aplicada em cenários com data de entrega, tempos de processamento e setup simulados, a heurística resulta em desvio médio de 18% da solução ótima gerada por enumeração para pelo menos 70% das simulações. / The competition in worldwide markets lead the companies to increase the competitiveness in order to take leading positions in their industries. In this sense, scheduling plays an important role leading the companies to reach their strategic goals through efficient utilization of manufacturing resources. This dissertation focuses on the scheduling unrelated parallel machines with sequence dependent setup times. First goal is to minimize the completion time and total weighted tardiness, through a three phase heuristic which (i) sort the jobs with WSPT, (ii) allocate the jobs to the machines and (iii) improve final solution with Tabu Search. Once applied to a real manufacturing environment composed by two unrelated parallel machines, in high vacuum plastic films metallisation process, the heuristic results in 1.1% of deviation from total weighted completion time and 4.6% of deviation from weighted tardiness, in relation to the optimal solution obtained from total enumeration. Next goal is the simultaneous minimization of weighted earliness and tardiness, through a three phase heuristic which (i) characterize the jobs, (ii) allocate the jobs to the machines with a modified version of Lee and Pinedo’s (1997) ATCS and (iii) improve final solution with Tabu Search. The application in real data results in 14% of deviation from the optimal solution obtained by enumeration. When applied to simulated scenarios of due date, processing and setup time, the heuristic results in average deviation of 18% from optimal solution obtained by enumeration to at least 70% of the simulations.

Problemas de sequenciamento são muito comuns, eles existem sempre que há uma escolha sobre a ordem em que várias tarefas podem ser realizadas. Seja o negócio uma companhia aérea, um hotel, um fabricante de computadores ou uma universidade, esses problemas fazem parte do cotidiano. A aplicação das técnicas de sequenciamento permite, por exemplo, a redução dos custos e o aumento na agilidade da cadeia de suprimentos, afetando as operações no inicio e no fim da cadeia de suprimentos pelo mundo inteiro. Este trabalho parte da intenção de abordar os princípios e as técnicas de Scheduling, com a finalidade de propor um modelo de sequenciamento para a solução de um problema em sistemas produtivos do tipo job shop com n tarefas e m máquinas, considerando os tempos de setup dependentes da sequência e tendo como horizonte de planejamento o curto prazo. O objetivo é o de minimizar a perda dos tempos não produtivos. Neste contexto, a pesquisa apresenta um enfoque tanto exploratório, quanto aplicado. Pode ser considerado exploratório, uma vez que a revisão da literatura é referência central para o desenvolvimento do modelo matemático. É aplicado considerando-se o desenvolvimento do modelo e avaliação de sua aplicabilidade. Sendo assim, a partir da definição do problema e desenvolvimento do modelo por meio do uso de técnicas matemáticas e abordagens da pesquisa operacional constatou-se que as conclusões tiradas podem inferir decisões para o problema real. Sendo que, as considerações aqui feitas têm por finalidade relatar os fatos constatados nos experimentos realizados, visando contribuir com futuras pesquisas na área. / Sequencing problems are very common, they happen every time there is a choice regarding the order in which several tasks can be performed. The business can be an airline, a hotel, a computer manufacturer or a university; these issues are part of their routine. The application of the sequencing techniques allows, for example, reducing the costs and fastening the supply chain all over the world. This work has an approach to Scheduling principles and techniques, with the objective of proposing a sequencing model for the solution of a problem in productive systems such as job shop with n tasks and m machines, considering setup times dependent on the sequence and adopting a short term planning. The goal is to minimize the waste of unproductive time. In this context, the research presents an approach both exploratory and applied. It can be considered exploratory, once that the literature review is a main reference to the development of a mathematical model. It is applied when we consider the development of the model and evaluation of its applicability. Thus, from the problem definition and the model development by the use of mathematical techniques and approaches of the operational research, we found that the conclusions drawn from the model might infer decisions for a real problem. The considerations shown here aim to report the facts given in the conducted experiments, intending to contribute to future researches in the area.

The thesis is a comparison between the business environment in Czech Republic and in France in term of SME's definition, legal forms of enterprise and different steps for a creation of enterprise in both countries. The thesis compares as well the tax and the social insurance in France to the Czech Republic system. The information founded is used by a Czech company to setup a branch office in France. The objective of the thesis is to evaluate the feasibility of this strategic concept of branch creation.

[EN] ABSTRACT Lots scheduling problem with setup times Cyclic dependent and independent of the sequence Paint Systems Applications. To define an efficient way to sequence a series of products in a production process affects in a relevant form, productivity and manufacturing costs. In the painting process of manufacturing companies of auto parts for the automotive industry the schedule and sequencing of products is done based on the customer master schedule. The manufacturing program is carried out following the requirements of models and colors that are requested and need to be delivered. In factories with these processes the information on the specifications of the products is often met with a very short window of time, in some cases as little as six hours. This requires a very flexible response. This thesis analyzes and seeks to improve the sequencing procedures to minimize changes that generate a setup in painting processes. The generation of setups in an auto parts painting plant may occur by two situations: 1) changes in the product model and 2) changes in the color used to paint. These cases occur independently from each other, in a specific time it is possible that either one case can occur or both simultaneously. It has been found that existing sequencing techniques do not contemplate the situation to optimize a production process of painting minimizing the number of changes that are generated by the two situations presented. The main motivation in this thesis is to develop procedures for solving the problem of bi_objective sequencing painting processes because existing techniques to minimize the number of setups do not consider this case. The application of conventional techniques is not sufficient to achieve efficiency at generating the best sequence. We part from the case of some specific number of companies to define the problem in working hypothesis. A review of the references included in related topics like "Sequencing in closed circuit processes", "cyclical scheduling" and "Optimization of setups" is done. Having given the hypothesis and reviewed the literature, the lack of models, methods and procedures in this environment is confirmed, with the exception of two references. The initial hypotheses were expanded to a wider focus of the problem: not only the basic case which looks for minimizing the number of changes of pattern and color, but a second problem is analyzed: to minimize the number of gaps that are generated when a setup occur either by changing color or pattern. In both cases, new mathematical models were designed and widely explained. In the model with gaps a very important contribution was done: the form of counting the empty spaces with uncertain horizon. It is explained in depth. Since both problems are NP_hard, if they are explored through optimization software, they quickly grow in resolution time. For this reason it is necessary the development of different heuristic procedures that provide a good solution where a reasonable computational time is warranted. For all of these processes it has been made a program code that simulates each case. In the problem without gaps 27 heuristic procedures were generated. For the problem with gaps, 19 procedures have been designed. For both problems conclusions were presented and the most efficient heuristics were justified by both points of view: statistically and analytically. A comparison with the theoretical optimum was made. Finally general conclusions are presented indicating possible future research in which the problems explained can be expanded and also indicating the possibility of extending the approach presented to other bi_objetive manufacturing lines, not necessarily painting systems. / [ES] RESUMEN Problema de Programación de Lotes Cíclicos con Tiempos de Preparación Dependientes e Independientes de la Secuencia con Aplicaciones a Sistemas de Pintura. Definir una manera eficiente de secuenciar una serie de productos en un proceso productivo impacta en forma relevante en la productividad y en los costes de fabricación. En los procesos de pintura de las empresas de fabricación de componentes para la industria automotriz se hace la secuenciación de productos con base al programa maestro que indican los clientes. El programa de fabricación se realiza siguiendo los requerimientos de modelos y colores que es necesario entregar. En las fábricas con estos procesos la información sobre las especificaciones de los productos se suele recibir con una ventana de tiempo muy corta, en algunos casos de tan solo seis horas. Esto requiere una flexibilidad de respuesta muy alta. Esta tesis analiza y busca mejorar los procedimientos de secuenciación para minimizar los cambios que generan un setup en los procesos de pintura. La generación de setups en una planta de pintura de componentes para automóvil puede ocurrir por dos situaciones: 1) cambios en el modelo del producto y 2) cambios en el color utilizado para pintar. Estos casos ocurren de forma independiente entre sí, es decir en un momento específico puede ocurrir un caso u otro o ambos al mismo tiempo. Se ha detectado que las técnicas de secuenciación existentes no contemplan la situación de optimizar un proceso productivo de pintura minimizando el número de cambios que se generan por las dos situaciones presentadas. La motivación principal en esta tesis es desarrollar procedimientos de solución al problema de secuenciación bi_objetivo en los procesos de pintura dado que las técnicas existentes para minimizar el número de setups no contemplan este caso. La aplicación de las técnicas clásicas resulta insuficiente para lograr eficiencia al generar una la mejor secuencia. Se parte del caso de algunas empresas específicas para delimitar el problema en una serie de hipótesis de trabajo. Se hace una revisión de las referencias sobre los temas afines que incluyen la secuenciación en procesos con circuito cerrado, la programación cíclica y la optimización de setups. Dadas las hipótesis de trabajo y la literatura existente se confirma la inexistencia de modelos, métodos y procedimientos en este entorno a excepción de dos referencias. Las hipótesis iniciales fueron ampliadas para cambiar el enfoque del problema: no solamente se aborda el caso básico de minimizar el número de cambios de modelo y de color sino que se analiza un segundo problema: minimizar el número de espacios vacíos que ocurren cuando hay un setup sea por cambio de modelo o de color. En ambos casos se diseñaron nuevos modelos matemáticos que son explicados ampliamente. Se hace una aportación muy importante en la forma de contar los espacios vacíos con horizonte incierto en el modelo con huecos que se explica a profundidad. Dado que ambos problemas son NP_hard y se exploran mediante software de optimización, rápidamente crecen en el tiempo de resolución. Por esta razón se justifica el desarrollo de distintos procedimientos heurísticos que proporcionan una buena solución computacional en un tiempo razonable. Para todos estos procedimientos se realiza un código de programación que permita simular cada caso. En el problema sin huecos se generaron 27 procedimientos heurísticos. En el caso con huecos fueron 19 procedimientos. Para ambos problemas se presentan conclusiones sobre las heurísticas más eficientes justificándolas tanto desde el punto de vista estadístico como de análisis comparativo con el óptimo teórico. Finalmente se presentan conclusiones generales donde se indican líneas futuras de investigación, en las que se pueden ampliar los problemas presentados y la posibilidad de extender el enfoque presentado a líneas de fabricación bi_objet / [CAT] RESUM Problema de Programació de lots cíclics amb temps de preparació dependents e independents de la seqüència amb Aplicacions a Sistemes de pintura. Definir una manera eficient de seqüenciar una sèrie de productes en un procés productiu impacta de forma rellevant en la productivitat i en els costos de fabricació. En els processos de pintura de les empreses de fabricació de components per a la industria automotriu es realitza la seqüenciació de productes en base al programa mestre que indiquen els clients. El programa de fabricació es realitza seguint els requeriments de models i colors que és necessari entregar. En les fabriques amb estos processos la informació sobre les especificacions dels productes es sol rebre amb una finestra de temps molt curta, en alguns casos de tan sols 6 hores. Açò requereix una flexibilitat de resposta molt alta. Esta tesis analitza i busca la manera de millorar els procediments de seqüenciació per a minimitzar els canvis que generen un setup en els processos de pintura. La generació de setups en una planta de pintures de components d'automòbil poden ocórrer per dos circumstancies: 1) canvi en el model del producte i 2) canvi en el color utilitzar per a pintar. Estos casos ocorren de forma independent entre sí, es a dir, en un moment específic pot ocórrer un cas, un altre o ambdós al mateix temps. S'ha detectat que les tècniques de seqüenciació existents no contemplen la situació d'optimitzar un procés productiu de pintura minimitzant el número de canvis que es generen per les dues situacions presentades. La motivació principal en esta tesis es desenvolupar procediments de solució al problema de seqüenciació bi_objectiu en els processos de pintura donat que les tècniques existents per a minimitzar el número de setups no contemplen este cas. L'aplicació de les tècniques clàssiques resulta insuficient per a aconseguir la eficiència al generar una millor seqüencia. Es parteix del cas d'algunes empreses especifiques per a delimitar el problema en una sèrie d'hipòtesis de treball. Es fa una revisió de les referencies sobre el tema afins que inclouen la seqüenciació en processos amb circuit tancat, la programació cíclica i l'optimització de setups. Donades les hipòtesis de treball i la literatura existent es confirma la inexistència de models, mètodes i procediments en este entorn a excepció de dos referencies. Les hipòtesis inicials foren ampliades per a canviar l'enfocament del problema: no únicament s'aborda el cas bàsic de minimitzar els número de canvis de model i de color sinó que s'analitza un segon problema: minimitzar el número d'espais buits que ocorren quan hi ha un setup causat per el canvi de model o color. En els dos casos es dissenyen nous models matemàtics en la forma de contar els espais buits amb horitzó incert en el model de buits que s'explica en profunditat. Donat que els dos problemes son NP_hard i s'exploren mitjançant programari d'optimització, ràpidament creixen en el temps de resolució. Per esta raó es justifica el desenvolupament de diferents procediments heurístics que proporcionen una bona solució computacional en un temps raonable. Per a tots estos procediments s'analitza un codi de programació que permet simular cada cas. En el problema sense buits es generen 27 procediments heurístics. En el cas amb buits han sigut 19 procediments. Per ambdós problemes es presenten conclusions sobre les heurístiques més eficients justificant-les tant des de el punt de vista estadístic, com d'anàlisis comparatiu amb el òptim teòric. Finalment es presenten conclusions general son s'indiquen línies d'investigació futures, en les que es poden ampliar els problemes presentats i la possibilitat d'ampliar l'enfocament presentat a línies de fabricació bi_objectiu no necessàriament de sistemes de pintura. / Martínez Ortiz, JA. (2015). Problema de programación de lotes cíclicos con tiempos de preparación dependientes e independientes de la secuencia con aplicaciónes a sistemas de pintura [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59068 / TESIS

L'ordonnancement est considéré comme l'une des tâches les plus importantes en industrie, notamment dans les ateliers de production. Son but principal est d'allouer les ressources disponibles aux tâches sur une période donnée, tout en optimisant un ou plusieurs objectifs tels que la minimisation des délais de production et les coûts de stockage. En France, ces industries contribuent de manière significative à l'économie régionale et nationale, faisant de la région Hauts-de-France la quatrième région économique française. Pour rester compétitives, ces sociétés doivent reposer, d'une part, sur un système de production fiable et disponible à tout moment, et d'autre part, sur de puissants outils d'aide à la décision permettant de réagir rapidement à toute situation imprévue telle qu'une panne ou un retard de livraison de matières premières, des annulation de commande, etc. Par ailleurs, la maintenance est un autre aspect étroitement lié à l'ordonnancement de la production. L'une des hypothèses les plus courantes dans la littérature est que les machines ou les ressources sont toujours disponibles à tout moment, or, en pratique, il peut être nécessaire de les arrêter en raison de pannes ou de maintenance préventive. Compte tenu du fait que les machines sont un élément essentiel du processus de production et que les coûts de maintenance représentent un grand pourcentage du budget total des opérations, il est souhaitable de bien coordonner la planification de la maintenance et l'ordonnancement de la production. Cette thèse aborde exactement ce problème, tout en considérant d'autres contraintes comme les temps de préparation dépendant de la séquence. L'objectif principal de ce travail est de concevoir et de développer des méthodes d'optimisation pour l'aide à la décision appliquées aux problèmes d'ordonnancement avec contrainte d'indisponibilité due à la maintenance préventive. Ces outils sont validés à travers des problèmes académiques et industriels simplifiés. Par conséquent, cette thèse a conduit au développement de nouveaux algorithmes et modèles basés sur la programmation linéaire en nombres entiers, des heuristiques et des métaheuristiques pour résoudre des problèmes d'ordonnancement de la production. / Production scheduling is considered as one of the most important tasks carried out in manufacturing systems. It allows available resources to perform a number of tasks, over a given period of time, while optimizing one or more objectives such as reducing production delays or costs associated with storage. In France, these industries contribute significantly to the regional and national economy, making the Hauts-de- France region the fourth French economic region. In order to remain competitive, these companies must be based, on one side, on a reliable production system that is available at any time, and on the other side, on powerful Decision Support Systems to react quickly to any unpredictable situation such as failures, late deliveries of raw material or orders cancellation, etc. Furthermore, maintenance is another aspect closely connected to production scheduling in real manufacturing settings. One of the most common assumptions in the scheduling literature is that the machines or resources are always available but, in practice, they may have to be stopped due to failures or to preventive maintenance. Taking into account that machines are an essential part of the production process and maintenance costs represent a large percentage of the total budget of operations, it is desirable to coordinate efficiently the maintenance planning and production scheduling. This thesis addresses exactly this problem, while considering other constraints such as sequence-dependent setup times between tasks. The main objective of this work is to design and develop optimization methods for decision support systems applied to scheduling problems with unavailability constraints due to preventive maintenance. The proposed models and tools have been validated through academic problems and on the basis of simplified industrial problems. Therefore, the output of the thesis is to develop new algorithms and models based on integer linear programming, heuristics and metaheuristics to solve production scheduling problems.

No description available.

<p>  </p> <p>Glass Fiber Reinforced Polymer (GFRP) rebars are frequently used to construct offshore structures, bridges, and airport terminals due to their high tensile strength, lightweight, and non-corrosive nature. GFRP rebars are also non-magnetic, electrically non-conductive, and have a higher strength-to-weight ratio than steel rebars. Consequently, many studies have been conducted to investigate the bond behavior of cast-in GFRP rebars, leading to the formulation of ACI 440. </p> <p>Post-installed rebar technology has become increasingly popular due to its flexibility in retrofitting and extending existing structures. Given the growing demand for post-installed technology and the superior qualities of GFRP rebars, there is a keen interest in understanding the behavior of post-installed GFRP rebars. Post-installed connections involve inserting a rebar in a pre-drilled hole in hardened concrete using an injectable epoxy. The post-installed system allows for construction between existing and new concrete for structural extension and rehabilitation purposes.</p> <p>Currently, only limited work has been performed on post-installed GFRP rebars at relatively small embedment depths. The adhesive mortars used for post-installation generally have a high bond strength. Most of the connections with post-installed rebars are made close to the edges of the members. Due to edge proximity, concrete-related failure modes (concrete splitting) govern, and the high bond strength of the post-installed system is not utilized. </p> <p>This study aims to understand the bond-splitting behavior of GFRP rebars post-installed using epoxy-based adhesive (DeWalt Pure200+). Experimental and Numerical investigations were conducted with various parameters that influence the bond-splitting. These parameters include but are not limited to, concrete cover, embedment depth, concrete strength, rebar diameter, and transverse confinement. </p> <p>An optimal experimental program was designed to test the minimum concrete cover, relative concrete cover, rebar diameter, rebar surface characteristics, and rebar embedment depth. The experimental investigation was carried out in two phases to determine the local bond strength by conducting confined pullout tests away from the edges at shallow embedment depths and the bond-splitting tests at varying parameters. Due to its low transverse strength, a unique grip using a steel pipe grouted with epoxy grout was used for the pullout tests. A new test specimen and test setup were designed to execute the experimental program at deeper embedment depths successfully.</p> <p>Numerical simulations were then performed using the macroscopic space analysis (MASA) program to investigate additional parameters and cases. The numerical models were first validated using results obtained from experimental investigation. Solid tetrahedral elements were used for modeling concrete elements with microplane models to simulate the damage in concrete. GFRP rebars were modeled using solid hexahedral elements with linear elastic material properties. The connection between concrete-to-GFRP rebar was modeled using 2-node bar elements embedded in the contact layer. The bond-slip curve gives the characteristic properties of the bar elements.</p> <p>The influence of individual parameters on the bond strength of the post-installed GFRP rebars was calculated, and comparisons were made with existing bond-splitting models for post-installed steel rebars. This thesis presents the details of the experimental program, the test specimen, the test setup, numerical modeling, and the results obtained on the GFRP bars post-installed with different sets of parameters. The studies prove the feasibility of using GFRP bars as post-installed for structural extensions/retrofitting and highlight certain aspects that must be considered while designing such connections.</p>

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No description available.