The sponsor of the thesis is the Composite Unit of AIRBUS Nantes plant, which manufactures aircraft composite. The basic process to manufacture composite parts is to lay-up raw composite material on a tool and involves very costly means and raw material. This process can be modeled as a two-stage hybrid flow shop problem with specific constraints, particularly prescription constraints on the jobs. This thesis restates the practical problem as a scheduling problem by doing hypotheses and restrictions. Then, it designs a mathematical model based on time-indexed variables. This model has been implemented in an IP solver to solve real based scenarios. A heuristic algorithm is developed for obtaining good solutions quickly. Finally, the heuristic is used to increase the execution speed of the IP solver. This thesis concludes by a discussion on the advantages and disadvantages of each option (IP solver vs. heuristic software) for the sponsor. / Master of Science

Over the last decade, the semiconductor industry has witnessed a steady increase in its complexity based on improvements in manufacturing processes and equipment. Progress in the technology used is no longer the key to success, however. In fact, the semiconductor technology has reached such a high level of complexity that improvements appear at a slow pace. Moreover, the diffusion of technology among competitors shows that traditional approaches based on technological advances and innovations are not sufficient to remain competitive. A recent crisis in the semiconductor field in the summer 2001 made it even clearer that optimizing the operational control of semiconductor wafer fabrication facilities is a vital key to success. Operating research-oriented studies have been carried out to this end for the last 5 years. None of them, however, suggest a comprehensive model and solution to the operational control problem of a semiconductor manufacturing facility. Two main approaches, namely mathematical programming and dispatching rules, have been explored in the literature so far, either partially or entirely dealing with this problem. Adapting the Shifting Bottleneck (SB) procedure is a third approach that has motivated many studies. Most research focuses on optimizing a certain objective function under idealized conditions and thus does not take into consideration system disruptions such as machine breakdown. While many papers address the adaptations of the SB procedure, the problem of re-scheduling jobs dynamically to take disruptions and local disturbances (machines breakdown, maintenance...) into consideration shows interesting perspectives for research. Dealing with local disturbances in a production environment and analyzing their impact on scheduling policies is a complex issue. It becomes even more complex in the semiconductor industry because of the numerous inherent constraints to take into account. The problem that is addressed in this thesis consists of studying dynamic scheduling in a job-shop environment where local disturbances occur. This research focuses on scheduling a large job shop and developing re-scheduling policies when local disturbances occur. The re-scheduling can be applied to the whole production horizon considered in the instance, or applied to a restricted period T that becomes a decision variable of the problem. The length of the restricted horizon T of re-scheduling can influence significantly the overall results. Its impact on the general performance is studied. Future extensions can be made to include constraints that arise in the semiconductors industry, such as the presence of parallel and batching machines, reentrant flows and the lot dedication problem. The theoretical results developed through this research will be applied to data sets to study their efficiency. We hope this methodology will bring useful insights to dealing effectively with local disturbances in production environments. / Master of Science

This is a study to determine the present and future status of offset printing as compared to letterpress printing in Texas, based on the opinions of qualified teachers of printing and commercial printers taken from sixteen groups of different sizes.

No / This article provides empirical data from the Tyneside Maritime Construction Industry (TMCI) to contribute to the union renewal/resilience debate. The aim of the study is a focus on the effectiveness of shop steward organisation in the industry, levels of activity in membership participation and its significance for union democracy, all of which are important factors in the debate. The paper supports the resilience argument and adds a further development to the debate by presenting evidence which suggests resilient renewal.

Today, labor union membership has dropped to its lowest level in over 40 years. Attempts to boost aggregate union membership through large scale organizing drives have largely failed. This has placed a great deal of pressure on unions to provide services to existing union members. This would seem to be especially true for labor unions operating in right-to-work states where union members can simply quit the union if they are not satisfied with the union's efforts. Accordingly, this project sought to explain the extent to which local unions have been successful in achieving desirable bargaining outcomes for their members through the exercise of bargaining power. The purpose of this project was to assess the relationship between sources of plant-level bargaining power and changes in collective bargaining outcomes in an open-shop environment. Sources of power were grouped into those over which the union had relatively greater control (strikes, union strength, and decertification attempts) and those over the employer had relatively greater control (bargaining unit employment, plant closure communications, and degree of labor intensity). A three-page survey questionnaire was employed to collect plant-level data from Virginia and Iowa representing sources of bargaining power relevant to specific time periods to help identify whether sources of bargaining power were more or less effective in securing bargaining outcomes favorable to the local union during episodes of union militancy. Results demonstrate that strike incidence and union strength, two consistent traditional predictors of various bargaining outcomes were ineffective as sources of union bargaining power at least for these samples. Strike duration did lead to greater bargaining outcomes for union members in Iowa. Decertification activity was so low in these samples that meaningful relationships were not possible. Changes in bargaining unit employment, over which the employer has relatively greater influence were directly related to bargaining outcomes in the Iowa sample of plants which did not experience strikes. In Virginia, the threat of a plant closure by an employer during an impasse lead to lower bargaining outcomes for union members as predicted. The degree of labor intensity was unrelated to changes in bargaining outcomes for either state. When considering all significant relationships (supportive and nonsupportive), strikes demonstrated a particularly disruptive influence. Research results suggested that future research should consider industrial, union affiliation, and regional differences in plant level studies. / Ph. D. / Pages xiv-xix missing.

The aim of the writer in giving the Stenquist Mechanical Aptitude Test as a basis for this study was to try to find a reliable method of selecting the boys to be admitted to the shop classes in vocational and technical high schools.

“Premium services will be offered by a cup of coffee” which is a relatively new business model in Taiwan. Thanks to the internet booming in recent years, it becomes less and less difficult for people to create new businesses; which leads to co-working spaces largely increasing their numbers in the world, especially in the U.S.A. and in Europe. It has become a global trend where people go to work and go to socialize. However, there are few co-working spaces existing in Asia, especially in Taiwan; their spaces are not cheap or one has to pay membership fee. You may or may not ever hear about the “Garage Café” in Beijing which is currently running a very successful business. It offers a low cost but high efficiency work space to entrepreneurs, start-up companies and many young people who have dreams of doing business. Our ideal is to introduce this type of business model in Taiwan; our goal is not aimed to make big profits but to bring a lot of business opportunities to boost the Taiwanese economy and to lead Taiwanese products to global markets.

O problema do sequenciamento da produção diz respeito à alocação das tarefas nas máquinas em um ambiente de fabricação, o qual vem sendo amplamente estudado. O sequenciamento pode variar em tamanho e complexidade dependendo do tipo de ambiente onde ele é aplicado, do número e tipos de restrições tecnológicas e da função objetivo do problema. A utilização de métodos de decisão para a solução de problemas de sequenciamento na indústria depende de modelos que sejam capazes de oferecer soluções para os problemas reais, que geralmente envolvem diversas restrições, os quais devem ser considerados simultaneamente. No presente trabalho o problema de sequenciamento da produção em ambientes flow shop permutacionais, com bloqueio com buffer zero, e com tempos de setup dependente da sequência e da máquina, com o objetivo de minimização do makespan é estudado, sendo este considerado um problema NP-Completo. O problema é pouco explorado na literatura. No presente trabalho é apresentado um procedimento de cálculo para o makespan e três métodos de solução para o problema: quatro limitantes inferiores para o procedimento Branch-and-Bound; quatro modelos MILP, sendo dois deles adaptados; e 28 modelos heurísticos construtivos adaptados para o problema. Os métodos desenvolvidos baseiam-se em propriedades matemáticas do problema que são apresentadas neste trabalho como limitante inferior e limitante superior. Dentre todos os modelos MILP, o modelo adaptado RBZBS1 obteve os melhores resultados para os problemas menores e o modelo desenvolvido TNZBS1 obteve os melhores desvios relativos médios do makespan para os problemas maiores, que não foram resolvidos dentro do limite de tempo computacional estipulado. O limitante inferior para o Branch-and-Bound LBTN2 foi melhor que os demais tanto no tempo computacional e no número de nós explorados como também no número de problemas não resolvidos e no desvio relativo médio do makespan. Foi realizado uma comparação entre o melhor modelo MILP e o melhor limitante inferior para o Branch-and-Bound, sendo que o último obteve melhores resultados para os problemas testados. Entre os métodos heurísticos adaptados, o PF foi o que obteve, de uma forma geral, os melhores resultados em todas as fases. / Production scheduling is defined as a problem of allocating jobs in machines in a production environment and it has been largely studied. The scheduling can vary in difficulty and complexity depending on the environment, the variety and types of technological restraints and the objective function of the problem. The use of decision making methods to solve scheduling problems in the industry needs models that are capable to solve real problems, that usually involve a big variety of restraints that have to be simultaneously studied. At the present work the scheduling problem in a permutational flow shop environment, considering blocking with zero buffer, and sequence and machine dependent setup times, with the objective of minimizing makespan is studied, which is considered a NP-Complete problem and little explored in literature. The work presents a calculation procedure for the makespan and three solution methods for the problem: four lower bounds for the Branch-and-Bound procedure; four MILP models, two of which are adapted; and 28 constructive heuristic methods adapted to the problem. The methods developed are based on mathematical properties of the problem that are presented in this work as a lower bound and an upper bound. Among all the MILP models, the adapted model RBZBS1 was the one to obtain the best results for the smaller problems, and the developed model TNZBS1 obtained the smallest mean relative deviation of the makespan for the bigger problems that were not solved within the specified computational time limit. The lower bound for the Branch-and-Bound LBTN2 obtained smaller computational times and number of explored nodes as well as the number of unsolved problems and the mean relative deviation for the makespan than all other lower bounds. Also, a comparison among the best MILP model and the best lower bound for the Branch-and-Bound was performed, being that the last obtained better results for the tested problems. Among the adapted heuristic methods, the PF heuristic was the one that obtained, in general, the better results in all phases.

Au sein d’un établissement hospitalier, le bloc opératoire représente un des secteurs les plus emblématiques et les plus coûteux. Le fonctionnement du bloc opératoire est orchestré par un programme opératoire qui consiste à construire un planning prévisionnel des interventions chirurgicales à réaliser pendant un horizon donné. La littérature abondante sur le sujet est unanime sur le fait que la construction du programme opératoire est une tâche complexe, car il s’agit non seulement de planifier et d’ordonnancer les interventions, mais aussi de satisfaire des exigences souvent antagonistes. Ce projet est le fruit d’une collaboration entre la Communauté d’Agglomération de Sarreguemines Confluences et la Région Lorraine, des membres du secteur hospitalier (Hôpital Robert Pax de Sarreguemines) et l’équipe Gestion Industrielle et Logistique (GIL) du Laboratoire de Génie Industriel, de Production et de Maintenance (LGIPM). L’objectif de cette recherche est d’apporter une aide aux gestionnaires du bloc opératoire, qui ont besoin de plus en plus des méthodes et des outils d’aide à la décision en vue d’optimiser leur fonctionnement. Pour répondre à ce besoin nous nous intéressons dans la première partie de cette thèse à la gestion des opérations électives en prenant en compte différentes contraintes et en particulier la disponibilité des chirurgiens. Nous nous plaçons dans le contexte d’une stratégie « open scheduling » et nous proposons deux modèles mathématiques permettant d’élaborer le programme opératoire. La complexité des modèles mathématiques et leur explosion combinatoire rendent difficile la recherche de l’optimum pour des tailles réalistes. Ceci nous a donc amené à proposer une heuristique constructive utilisant le modèle proposé et permettant d’obtenir des solutions là où la méthode exacte ne nous le permettait pas. Dans la seconde partie de cette thèse, nous considérons l’intégralité du processus opératoire (brancardage vers le bloc opératoire, préparation et anesthésie, acte chirurgicale et réveil). Nous modélisons ce processus comme un flow shop hybride à 4 étages avec contrainte de blocage de type RSb, et nous le résolvons à l’aide d’un algorithme génétique dont l’objectif est de synchroniser toutes les ressources nécessaires, en respectant au mieux le programme opératoire prévisionnel. Outre les opérations électives, nous nous intéressons dans la dernière partie aux opérations urgentes. Nous proposons un outil d’aide à la décision pour la gestion des opérations urgentes. En prenant en considération la pathologie et la gravité de l’état du patient, nous distinguons principalement 3 degrés d’urgences et proposons pour chacune un algorithme permettant d’intégrer en temps réel ces opérations dans le programme prévisionnel, tout en minimisant différents critères (temps d’attente avant affectation, heures supplémentaires, décalage par rapport aux anciennes dates de débuts) / The operating theater is one of the most critical and expensive hospital resources. Indeed, a high percentage of hospital admissions are due to surgical interventions. Rising expenditures spur health care organizations to organize their processes more efficiently and effectively. This thesis is supported by the urban community of Sarreguemines-France and the region of Lorraine-France, and is carried out in collaboration with the Centre Hospitalier de Sarreguemines - Hôpital Robert Pax. In the first part of this work, we propose two mathematical programming models to help operating theater managers in developing an optimal operating rooms scheduling. We also propose a constructive heuristic to obtain near optimal results for realistic sizes of the problem. In the second part of our work, the whole scheduling process is modeled as a hybrid four-stage flow shop problem with RSb blocking constraint, and is solved by a genetic algorithm. The objective is to synchronize all the needed resources around the optimal daily schedule obtained with the proposed mathematical model. The last part of our work is dedicated to non-elective surgeries. We propose a decision support tool, guiding the operating room manager, to handle this unpredictable flow of patients. Non-elective patients are classified according to their medical priority. The main contribution of the proposed decision support tool is to provide online assignment strategies to treat each non elective patient category. Proposed assignments are riskless on patient’s health. According to non-elective surgery classes, the proposed adjusted schedule minimizes different criteria such as patient’s waiting time, deviation from the firstly scheduled starting time of a surgery and the amount of resulting overtime

Especialmente nas últimas quatro décadas, muitos estudos se voltaram às variáveis determinantes para a implementação efetiva de sistemas flexíveis de manufatura, tais como seu design, sequenciamento e controle. Neste ínterim, o manejo apropriado do conjunto de ferramentas necessárias para a fabricação de um respectivo lote de produtos foi destacado como fator crucial no desempenho do sistema de produção como um todo. Neste trabalho, abordamos a otimização do número de inserções e remoções de ferramentas no magazine de uma ou mais máquinas numericamente controladas, admitindo-se que uma parcela significativa do tempo de produção é dispensada com estas trocas de ferramentas. De forma mais precisa, a minimização do número de trocas de ferramentas consiste em determinar a ordem de processamento de um conjunto de tarefas, bem como o carregamento ótimo do(s) compartimento(s) de ferramentas da(s) máquina(s), a fim de que o número de trocas seja minimizado. Como demostrado na literatura, mesmo o caso restrito à existência de apenas uma máquina de manufatura (MTSP, do inglês Minimization of Tool Switches Problem) é um problema NP-difícil, o que pode justificar o fato observado de que a maioria dos métodos de solução existentes o abordam de maneira heurística. Consequentemente, concluímos que a extensão ao contexto de múltiplas máquinas é também um problema NP-difícil, intrinsecamente complicado de se resolver. Nosso objetivo consiste em estudar formas eficientes de otimizar o número de trocas de ferramentas em ambientes equipados com máquinas flexíveis de manufatura. Para tanto, abordamos o problema básico, MTSP, e duas de suas variantes, em níveis crescentes de abrangência, que consideram o sequenciamento de tarefas em um conjunto de: (i) máquinas paralelas e idênticas (IPMTC, do inglês Identical Parallel Machines problem with Tooling Constraints); e (ii) máquinas paralelas e idênticas inseridas em um ambiente do tipo job shop (JSSPTC, do inglês Job Shop Scheduling Problem with Tooling Constraints). Classificamos as principais contribuições desta tese com respeito a três aspectos. Primeiramente, empurramos as fronteiras da literatura do MTSP propondo formulações matemáticas para os problemas IPMTC e JSSPTC. Desenvolvemos, também, algoritmos baseados em diferentes técnicas de resolução, como redução de domínio, Path relinking, Adaptive large neighborhood search e a elaboração de regras de despacho. Por último, com o intuito de bem avaliar a eficiência e o alcance de nossos métodos, propomos três novos conjuntos de instâncias teste. Acreditamos, assim, que este trabalho contribui positivamente com pesquisas futuras em um cenário abrangente dentro da minimização das trocas de ferramentas em um sistema flexível de manufatura. / Several studies, especially in the last four decades, have focused on decisive elements for the effective implementation of flexible manufacturing systems, such as their design, scheduling and control. In the meantime, the appropriate management of the set of tools needed to manufacture a certain lot of products has been highlighted as a crucial factor in the performance of the production system as a whole. This work deals with the optimization of the number of insertions and removals from the magazine of one or more numerical controlled machines, assuming that a significant part of the production time is wasted with such tool switches. More precisely, the minimization of tool switches problem (MTSP) consists on determining the processing order of a set of jobs, as well as the optimal loading of the magazine(s) of the machine(s), so that the total number of switches is minimized. As formally demonstrated in the literature, the MTSP is a NP-hard problem even when considering the existence of only one manufacturing machine, which could justify the fact that most of the solution methods tackles it heuristically. We thus conclude that its extension to the case of multiples machines is also NP-hard and, therefore, a problem intrinsically difficult to solve. Our goal consists in studying efficient ways to optimize the number of tool switches in environments equipped with flexible manufacturing machines. For that, we address the basic problem, MTSP, and two MTSP variants, in increasing levels of reach, that consider the job sequencing in a set of: (i) identical parallel machines (Identical Parallel Machines problem with Tooling Constraints, IPMTC); and (ii) identical parallel machines inserted in a job shop environment (Job Shop Scheduling Problem with Tooling Constraints, JSSPTC). The main contributions of this thesis are classified according three aspects. First, we pushed the frontier of the MTSP literature by proposing mathematical formulations for IPMTC and JSSPTC. We also developed algorithms based on different solution techniques, such as domain reduction, Path Relinking, Adaptive Large Neighborhood Search and dispatching rules. Finally, to fully evaluate the effectiveness and limits of our methods, three new sets of benchmark instances were generated. We believe that this work contributes positively to the future of research in a broad scenario inside the minimization of tool switches in flexible manufacturing systems.