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.

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.

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<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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