The growth of global competition has led to remarkable changes in the way manufacturing companies operate. These changes have affected maintenance and made its role even more crucial for business success. To remain competitive, manufacturing companies must continuously increase the effectiveness and efficiency of their production processes. Furthermore, the introduction of lean manufacturing has increased concerns regarding equipment availability and, therefore, the demand for effective maintenance. That maintenance is becoming more important for the manufacturing industry is evident in current discussions on national industrialization agendas. Digitalization, the industrial internet of things (IoT) and their connections to sustainable production are identified as key enablers for increasing the number of jobs in industry. Agendas such as “Industry 4.0” in Germany and “Smart Industry” in Sweden are promoting the connection of physical items such as sensors, devices and enterprise assets, both to each other and to the internet. Machines, systems, manufactured parts and humans will be closely interlinked to collaborative actions. Every physical object will formulate a cyber-physical system (CPS), and it will constantly be linked to its digital fingerprint and to intensive connection with the surrounding CPSs of its on-going processes. That said, despite the increasing demand for reliable production equipment, few manufacturing companies pursue the development of strategic maintenance. Moreover, traditional maintenance strategies, such as corrective maintenance, are no longer sufficient to satisfy industrial needs, such as reducing failures and degradations of manufacturing systems to the greatest possible extent. The concept of maintenance has evolved over the last few decades from a corrective approach (maintenance actions after a failure) to a preventive approach (maintenance actions to prevent the failure). Strategies and concepts such as condition based maintenance (CBM) have thus evolved to support this ideal outcome. CBM is a set of maintenance actions based on the real-time or near real-time assessment of equipment conditions, which is obtained from embedded sensors and/or external tests and measurements, taken by portable equipment and/or subjective condition monitoring. CBM is increasingly recognized as the most efficient strategy for performing maintenance in a wide variety of industries. However, the practical implementation of advanced maintenance technologies, such as CBM, is relatively limited in the manufacturing industry. Based on the discussion above, the objective of this research is to provide frameworks and guidelines to support the development and implementation of condition based maintenance in manufacturing companies.  This thesis will begin with an overall analysis of maintenance management to identify factors needed to strategically manage production maintenance. It will continue with a focus on CBM to illustrate how CBM could be valued in manufacturing companies and what the influencing factors to implement CBM are. The data were collected through case studies, mainly at one major automotive manufacturing site in Sweden. The bulk of the data was collected during a pilot CBM implementation project. Following the findings from these efforts, a formulated maintenance strategy is developed and presented, and factors to evaluate CBM cost effectiveness are assessed. These factors indicate the benefits of CBM, mostly with regard to reducing the probability of experiencing maximal damage to production equipment and reducing production losses, particularly at high production volumes. Furthermore, a process of CBM implementation is presented. Some of the main elements in the process are the selection of the components to be monitored, the techniques and technologies for condition monitoring and their installation and, finally, the analysis of the results of condition monitoring. Furthermore, CBM of machine tools is presented and discussed in this thesis, focusing on the use of vibration monitoring technique to monitor the condition of machine tool spindle units. / INNOFACTURE - innovative manufacturing development

The methodology and the processes that are followed in the maintenance of government-operated district hospitals in the Eastern Cape Province of South Africa are outlined while the strategies that are employed to roll-out the maintenance plan have been investigated. The challenges in managing hospital maintenance are identified so that it can be improved and advice be given on the strategies currently being used. The objectives of the research were to determine the effectiveness of machinery maintenance in government-operated district hospitals. The study has been carried out by investigating 50 district hospitals within the Eastern Cape Province, with the aim of obtaining knowledge of practices in relation to the strategic plans and best practices in the maintenance industry. The following factors identified by the maintenance staff were found to be most important in maintenance management practices; realistic budgets, adherence to occupational health and safety regulations, engagement of qualified and skilled maintenance staff, good record management in relation to the equipment under maintenance, availability of tools and materials and keeping abreast with the latest technologies and trends of machinery advancement. The study also revealed that the majority of the hospitals use a combination of in-house and outsourced personnel during maintenance, the outsourced part being under contract from the National Department of Public Works Repair and Maintenance Plan (RAMP) projects. Service kits and recommended replacement parts for machinery are rarely stocked on the hospital premises while only minor spare parts that include replacement bulbs, electrical fittings, plumbing fittings and paint are readily available. In addition, the maintenance staff members have little or no input in maintenance budgeting, this aspect is controlled by hospital management. For maintenance to be effective, strategic planning that takes into account carefully thought-out maintenance management systems is the first step in the direction of setting out definite tangible objectives and goals. The real challenge lies in the implementation and sustainability of the maintenance management system and the monitoring thereof.

Production Line Systems (PLS) are ubiquitous in today’s manufacturing industry. The need for enhanced efficiencies and higher throughput in such systems has increased their complexity and size that has made performance analysis challenging for practitioners. This thesis introduces a novel approach based on Product Service System (PSS) design and analysis which simplifies Production Line System study and identifies opportunities for performance improvement that can be quantified based on the hardware and maintenance system performance. The approach involves modelling and simulation techniques based on reliability engineering principles and systems thinking. In order to apply the principles of PSS approach to PLS, it is essential to draw a comparison between PLS and PSS, so as to take account of the differences while applying the new approach; a literature review has been carried out on PSS Design and Analysis, that identified the state of the art modelling and simulation techniques in PSS. Additionally, a separate literature review on maintenance system and production line was carried out. This enabled the PSS methodology to be applied to PLS by incorporating the differences. A systems thinking approach has been employed to create the static simulation model of the integrated production line system by means of schematic representations. Key improvement areas, identified from the static simulation model have been modelled dynamically to incorporate the stochastic behaviour of the system. All the dynamic models are developed using a Discrete Event Simulation platform. These models were supported by Monte Carlo Simulation, queuing principles, probabilistical and statistical methods pertinent to reliability engineering. The novel integrated simulation model consists of a production line model and a maintenance system model. The production line model simulates two types of failures in addition to the outages in the system: breakdowns and short stops. The maintenance system model simulates the maintenance actions in the production line by considering the resources availability, repair time, and resources travelling time amongst others. In addition, the maintenance model is capable of optimizing the preventive maintenance interval for maintainable failures for cost, availability and criticality while taking into account the maintenance effectiveness value from the failure data. The simulation model is validated using an industrial case study which consists of a large production line for beer. Sensitivity studies on the simulation model enabled the case study company to focus on strategies for throughput improvement by improving the reliability and maintainability, optimal resources allocation and maintenance interval optimization in targeted areas in the large and complex system. The model developed is generic and can easily be applied to analyse other industrial production line systems. It can also be used as a design tool for new production lines.

Nesta dissertação é apresentada a análise, desenvolvimento e aplicação de ferramentas para melhoria no sistema de gestão da manutenção de subestações do sistema elétrico de uma empresa do ramo de bebidas composta por algumas dezenas de plantas que trabalham em regime ininterrupto. O sistema de gestão da manutenção aplicado nesta empresa é condizente com o que sugere a literatura e apresenta resultados satisfatórios em vários setores. No entanto, pode-se constatar algumas dificuldades e fatores negativos na gestão do sistema elétrico da empresa, que funciona em três turnos. As limitações impostas ao sistema de gestão da manutenção comprometem sua eficiência gerando um nível indesejado de indisponibilidade por energia elétrica. A manutenção preventiva é realizada em paradas de fabricas de tempo reduzido. A localização geográfica bem como a extensão do sistema elétrico das plantas impõe que sejam contratadas diversas empresas para realizar estas manutenções. Esta diversidade traz grande dificuldade no tratamento dos dados de ensaios e de anomalias detectadas e apresentados nos relatórios de manutenção. O objetivo principal desta dissertação é apresentar uma análise crítica do sistema atual de gestão da manutenção das subestações do setor elétrico e uma proposta para melhorar este sistema de gestão quanto à sua aplicação no setor elétrico. Esta proposta se baseia na correção das distorções no índice de indisponibilidade e em uma ferramenta para aperfeiçoar o tratamento das informações resultantes da manutenção preventiva para sua utilização tanto no monitoramento do sistema quanto para embasar o processo decisório de priorização das manutenções corretivas e de investimento. O trabalho apresenta ainda o emprego dos conceitos que fundamentam a ferramenta proposta antes da aplicação da mesma e os impactos em indisponibilidade resultantes da aplicação destes conceitos. / This work presents the analysis, development and application of tools to improve the electrical substations maintenance management system of a beverage company composed of dozens of plants working continuously. The maintenance management system used in this company is consistent with what the literature suggests and provides satisfactory results in various sectors. However, we can notice some difficulties and negative factors in managing the electrical system of the company, which operates in three shifts. The limitations imposed on the maintenance management system compromise their efficiency generating an undesirable level of electrical power unavailability. Preventive maintenance is carried out in short time factory interruptions. The geographical location and the extent of the electrical system of the plants requires several companies to be hired to perform these maintenances. This diversity brings great difficulty in the treatment of tests and deficiencies data presented in the reports. The main objective of this dissertation is to present a critical analysis of the current substations maintenance management system in the electrical sector and a proposal to improve the management system in its application in the electrical sector. This proposal is based on correcting the distortions in the unavailability index and a tool to enhance the processing of information resulting from preventive maintenance to be used both for monitoring the system and to support the decision making process of prioritization of corrective maintenance and investment. The paper also describes the use of the concepts on which the proposed tool is based before implementation and impact on unavailability resulting from the application of these concepts.

This diploma thesis deals with a proposal how to improve technology of mainte-nance of trucks and buses of ICOM transport branch in Humpolec. Main aim of this diploma thesis is the analysis of current technology of maintenance, especially the oil system and it´s modification. This aim was reached by suggestion of the new technol-ogy of oil system, technical eguipment and elaboration of new technical methods. Modern and efficient technology of oil system for trucking and repairation is the solution of this topic. That is the set of processes with operating system (monitoring) whitch guarantees safe, enviroment storage of oils, greases and antifreezer, their de-cantation and precise dosing during distribuion.

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.

Les dommages de l'ADN peuvent s’accumuler dans les cellules souches hématopoïétiques(CSH) suite aux stress externes ou métaboliques et perturber leur fonctionnement et/ou leur maintien.La réparation par excision de nucléotides (NER), initiée par l’arrêt de la transcription (TCR) ou par lareconnaissance de distorsions des régions non transcrites (GGR) de l’ADN, est nécessaire àl’hématopoïèse à long terme. XPC, un facteur clé du système GGR, participe à d’autres réponses austress oxydatif. Le laboratoire a montré que la perte de XPC provoque l’accumulation de mutations, unstress métabolique et la carcinogenèse. Notre objectif est d’évaluer son expression et son rôle dans lemaintien et la différenciation des CSH. Nos résultats montrent qu’il est plus exprimé dans les cellulesimmatures CD34+ que dans les CD34- matures. Aussi, XPC apparaît sous trois poids moléculairesdifférents certainement liés à des modifications post-traductionnelles. Son extinction par ARNinterférence n'affecte ni la prolifération ni la capacité progénitrice in vitro des cellules CD34+.Cependant, les cellules déficientes implantées chez des souris immunodéficientes disparaissentprogressivement suggérant une perte des CSH ou de leur capacité de différenciation. Postulant queles mutations s’accumulent avec le temps, nous avons étudié l’hématopoïèse chez des sourisdéficientes en XPC jeunes et âgées. Les différences décrites dans l’hématopoïèse chez les individusjeunes et âgés sont retrouvées mais, de manière surprenante, aucune différence entre les animauxsauvages et mutés quelque soit l’âge ou le stress génotoxique n’est observée. Les résultats obtenussur les cellules humaines démontrent un rôle potentiel de XPC dans l’hématopoïèse, mais denouvelles investigations sont nécessaires pour mieux comprendre les mécanismes impliqués, et lapossible participation de XPC dans la leucémogenèse. / DNA damage may accumulate in hematopoietic stem cells (HSC) due to external ormetabolic stresses, leading to perturbation in their function and/or maintenance. Nucleotide excisionrepair (NER), initiated in the DNA by the stop of transcription (TCR) or by the recognition of distortionsin transcribed regions (GGR), is necessary for long-term hematopoiesis. XPC, a key factor in GGR, isimplicated in oxidative stress. The laboratory has demonstrated that XPC loss leads to theaccumulation of mutations, metabolic stress and carcinogenesis. Our objective is to evaluate XPCexpression and its role in HSC maintenance and differentiation. Results showed that XPC is highlyexpressed in immature CD34+ cells compared to mature CD34- cells. In addition, XPC appeared withthree different molecular weights, certainly linked to post-translational modifications. XPC silencing byshRNA did not affect the proliferation or the progenitor ability of CD34+ cells in vitro. However, deficientcells transplanted in immunodeficient mice disappeared progressively, suggesting the loss of HSCs ortheir differentiation capacity. Postulating that mutations accumulate with time, we have studiedhematopoiesis in young and aged XPC deficient mice. Differences described in young and agedhematopoiesis systems were found but, surprisingly, no difference was observed between wild typeand mutant mice at any age or genotoxic stress. Data from human cells demonstrate a potential rolefor XPC in HSC but new investigations are necessary to better understand the mechanisms implicatedand if XPC may participate in leukemogenesis.

Cette thèse s’inscrit dans le cadre de la disposition CIFRE entre la société Robert Bosch et l’Université de Caen Normandie au sein du laboratoire GREYC puis LAC. Elle comprend deux volets, l'un étant à caractère fondamental et porte sur la synthèse d'observateurs. Quant à l'autre volet, il est à caractère plus appliqué et porte sur la mise en œuvre d’un réseau de capteurs et assurer l’acheminement des informations provenant de ces derniers. Ce dernier est effectué au moyen du réseau, qu’il soit câblé ou sans fil.Dans le premier volet de l'étude, on s'est intéressé à une classe assez générale de systèmes temps-variant et affines en l'état, dont la sortie est mesurée avec un retard et échantillonnée. La nouveauté dans cette classe de systèmes est double :(i) l'équation d'état est sujette à une injection du signal de sortie et se retrouve de ce fait dépendante des sorties futures qui sont indisponibles;(ii) les sorties futures interviennent, au niveau de l'équation d'état, non seulement sous la forme usuelle d'une fonction indépendante de l'état, mais aussi à travers la matrice d'état ellemême qui, de ce fait, apparaît comme une quantité inconnue du modèle.Ces deux nouveautés du modèle entrainent en fait la perte du caractère « affine en l'état » de ce dernier et font que l'on se retrouve confronté à un problème de synthèse d'observateurs jamais résolu antérieurement. La solution que nous proposons est un observateur de type « Filtre de Kalman » augmenté d'un prédicteur inter-échantillons et d'opérateurs de saturations. Nous analysons la stabilité exponentielle du système d'erreur d'estimation d'état en utilisant le théorème du petit gain et des outils de la stabilité de Lyapunov. L'analyse met en évidence l'existence d'intervalles d'admissibilité dans lesquels doivent se situer les valeurs admissibles du retard et de la période d'échantillonnage, afin de garantir la convergence exponentielle de l'observateur.Dans le deuxième volet, nous nous intéressons à la maintenance prédictive au travers d’applications pratiques via la mise en place d’un réseau de capteurs. Le but de ce réseau est d’effectuer de la maintenance prédictive sur les équipements sensibles. Ce dernier est un composant essentiel à la mise en œuvre d’applications IoT et Industrie 4.0.Des applications de l’IoT et de l’Industrie 4.0 sur le site Robert Bosch de Mondeville sont évoqués ainsi que le développement d’un simulateur de perturbations réseau afin de tester la robustesse de la communication d’un capteur vers un client. / This thesis is part of the CIFRE agreement between the company Robert Bosch and the University of Caen Normandy in the laboratory GREYC then LAC. It consists of two parts, one which is of a fundamental nature and concerns the synthesis of observers. For the other part, it is more applied and concerns the implementation of a sensors network and ensure the routing of information from them. This is done through the network, whether wired or wireless.In the first part of the study, we looked at a fairly general class of time-varying and affine systems as they are, whose output is measured with a delay and sampled. The novelty in this class of systems is twofold:(i) the state equation is subject to an output signal injection and is therefore dependent on future outputs that are unavailable;(ii) future outputs occur at the state equation not only in the usual form of a stateindependent function, but also through the state matrix itself, which fact, appears as an unknown quantity of the model.These two novelties of the model cause in fact the loss of the "affine in the state" character of this last one, and make that one is confronted with a synthesis problem of observers never resolved previously. The solution we propose is a "Kalman filter" type observer augmented by an inter-sample predictor and saturation operators. We analyze the exponential stability of the state estimation error system by using the small gain theorem and tools of Lyapunov stability. The analysis highlights the existence of eligibility intervals in which the allowable values of the delay and the sampling period must be located in order to ensure the exponential convergence of the observer.In the second part, we are interested in predictive maintenance through practical applications via the installation of a sensor network. The purpose of this network is to perform predictive maintenance on sensitive equipment. The latter is an essential component for the implementation of IoT and Industry 4.0 applications.The purpose of this sensor network is to perform predictive maintenance on sensitive equipment. The latter is an essential component for the implementation of IoT and Industry 4.0 applications. Moreover, an observer of sampled data for affine systems in the state with output injection was studied on the basis of observers.Applications of IoT and Industry 4.0 on the Robert Bosch site in Mondeville are discussed as well as the development of a network disturbance simulator to stress the robustness of the communication of a sensor to a client.

The objectives of this research were to 1) compile winter maintenance data for the Utah Department of Transportation (UDOT) to directly compare concrete and asphalt pavements with regards to deicer usage and 2) determine if there is a statistical difference in deicer usage on concrete and asphalt pavements. To this end, three data sources were consulted for this research: Material Maintenance Quality Assurance (MMQA) database, UDOT road database, and Google Maps. The final compiled data set prepared for analysis in this research contained deicer quantities by deicer type, pavement surface areas by pavement material type, traffic, longitude, latitude, and elevation data. The deicer data evaluated in this analysis represented the total quantities of each deicer distributed during the 8-year period during which the MMQA database was used by UDOT.Several multiple linear regression analyses were performed to determine if concrete or asphalt pavements required different amounts of deicers, including salt, Redmond salt, brine, wetted salt, magnesium chloride, sand, pre-mix, and wetted pre-mix, during the winter seasons evaluated in this research. Because plow routes were not equal in total pavement area, a variable called “concrete proportion” was created. Similarly, traffic and deicer quantities were divided by total pavement area in lane miles to account for the variation in maintenance station sizes and to allow for direct comparison of the various maintenance stations. After the values of the independent variables were finalized, full and reduced models were created for the total amount of all deicers per lane mile and the amounts of each of the eight individual deicers per lane mile based on the statistical significance of the respective independent variables. A total of 18 regression models were completed for this research.From the results of the statistical analyses, concrete proportion was statistically significant in models for three of the dependent variables, including brine, wetted salt, and wetted pre-mix. However, neither the full nor the reduced regression model prepared for the sum of all deicers had concrete proportion as one of the significant variables. The absence of concrete proportion as an independent variable in these models shows that, on average, after correcting for differences in traffic volume and pavement area, deicer usage in Utah is not affected by pavement type. Therefore, except in areas where applications of brine, wetted salt, and wetted pre-mix are common, winter maintenance costs should not be a factor in the determination of pavement type.

JYSK is one of North Europe's largest furniture suppliers with over 2 800 stores. The central warehouse located in Nässjö delivers to all of Sweden and although the company is well established on the market, there are shortcomings in the maintenance work. This cause for unnecessary breaks in the logistics chain which contributes to a lower availability. The purpose of this study was to bring forth suitable action proposals that could help JYSK in their effort in establishing a functioning maintenance.  To answer the study's purpose three questions had been presented: 1.     What type of stops occurs and what metrics can be used to calculate the availability? 2.     How is the suppliers’ maintenance-plan designed for each equipment? 3.     Which maintenance work should be prioritized by JYSK, based on the existing and suppliers' maintenance plans?  The study´s major demarcation was towards fully automated equipment only as well as no metrics was calculated and presented.  A case study consisting of a literature study was accomplished with the purpose to gather data to be able to answer the questions. Qualitative methods that was accomplished was an interview, observations, and document collection.  The result presented in this study was a well-developed maintenance plan, checklists based on the recommendation of the supplier and suggestions on follow ups that focuses on visualisation and metrics.    The study's conclusion was that JYSK had all the necessary tools and instructions on how to develop and implement a working maintenance plan provided. The company only had to implement the given recommendations in their everyday routine. It was necessary for JYSK to identify the causes behind the stops to be able to eliminate them.