Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2019-03-25T13:14:24Z No. of bitstreams: 1 Bruno Pinho_.pdf: 1812872 bytes, checksum: d23670c9c146445b842db6b585875fff (MD5) / Made available in DSpace on 2019-03-25T13:14:24Z (GMT). No. of bitstreams: 1 Bruno Pinho_.pdf: 1812872 bytes, checksum: d23670c9c146445b842db6b585875fff (MD5) Previous issue date: 2019-01-15 / Nenhuma / O objetivo desta dissertação é desenvolver um método para definir a estratégia de manutenção de uma empresa metal-mecânica do ramo de forjados. Para uma linha de forjamento e o setor de corte de matéria prima foram definidas as estratégias de manutenção para treze máquinas. Na linha de forjamento foram identificadas as máquinas críticas, por indicação da empresa e análise de gargalo, aplicando o FMEA para identificação dos modos de falha das mesmas. A metodologia de pesquisa é modelagem quantitativa e uma pesquisa exploratória para a abordagem qualitativa. A técnica de pesquisa quantitativa é a modelagem probabilística do tempo entre falhas e do tempo para o reparo para as máquinas e do tempo médio entre falhas para o sistema. As máquinas do setor de corte estão dispostas em paralelo, as da linha de forjamento em série. Seis máquinas estão no período de mortalidade infantil, o que requer a estratégia de manutenção corretiva. Sete máquinas estão no período de maturidade, o que requer a estratégia de manutenção preditiva. O sistema produtivo foi avaliado conforme o diâmetro do aço a ser processado. O sistema produtivo que apresentou o melhor valor de tempo médio entre falhas foi para produção de itens cujo aço é de Ø64mm a Ø120mm, 14,39h. Já a maior disponibilidade geral do sistema é para a produção de itens cujo aço é de Ø35mm a Ø63mm, 90,63%. A definição das máquinas para aplicação do FMEA na linha de forjamento se deu através da análise do gargalo da linha e por indicação da empresa, uma máquina que não possui backup, o martelo hidráulico e o forno a indução. No martelo hidráulico os modos de falha de maior risco, foram encontrados, nas válvulas hidráulicas de acionamento, referente à válvula pneumática piloto, e no sistema de acionamento elétrico, referente à falha no pedal elétrico. No forno a indução se destacou o modo de falha na estação de aquecimento. A análise dos modos de falha e seus efeitos possibilitaram propostas de melhorias nos processos de manutenção das duas máquinas identificadas como críticas na linha de forjamento. A realização do FMEA possibilitou uma complementação das estratégias de manutenção adequadas para as máquinas analisadas, propondo práticas pontuais de manutenção preventiva. / The objective of this dissertation is to develop a method to define the strategy of maintenance of a metal-mechanic company of the forging sector. The maintenance strategies for thirteen machines were defined for a forging line and the raw material cutting sector. In the forging line, critical machines were identified by company identification and bottleneck analysis, applying the FMEA to identify failure modes. The research methodology is quantitative modeling and an exploratory research for the qualitative approach. The technique of quantitative research is the probabilistic modeling of the time between failures and the time for the repair for the machines and the mean time between failures for the system. The machines in the sector of cut are arranged in parallel, those of the forging line in series. Six machines are in the infant mortality period, which requires a corrective maintenance strategy. Seven machines are in the maturity period, which requires the predictive maintenance strategy. The production system was evaluated according to the diameter of the steel to be processed. The productive system that presented the best average time between failures was to produce items whose steel is Ø64mm to Ø120mm, 14.39h. Already the greater general availability of the system is for the production of items whose steel is of Ø35mm to Ø63mm, 90,63%. The definition of the machines for the application of the FMEA in the forging line occurred through the analysis of the line bottleneck and the company's indication, a machine that does not have backup, the hydraulic hammer and the induction furnace. In the hydraulic hammer, the most dangerous fault modes were found in the hydraulic control valves for the pilot pneumatic valve and in the electric drive system for the failure of the electric pedal. In the induction furnace the failure mode in the heating station was highlighted. The analysis of failure modes and their effects made possible improvements in the maintenance processes of the two machines identified as critical in the forging line. The realization of FMEA made it possible to complement the adequate maintenance strategies for the analyzed machines, proposing specific practices of preventive maintenance.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19291号 / 工博第4088号 / 新制||工||1630(附属図書館) / 32293 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 小林 潔司, 教授 大津 宏康, 准教授 松島 格也 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

This thesis aims to benchmark the Overall Equipment Effectiveness of the production and maintenance strategy for a company in the small to midsize enterprise, going through an expansion phase and at the same time starting to implement Total Productive Maintenance along with the organisation. The purpose is to give guidance through benchmarking maintenance for the future and during the start-up of the maintenance organisation. This study was formed with two research questions about the Overall Equipment Effectiveness at the production and how a future digital measuring of the Overall Equipment Effectiveness can occur. Interviews and questionnaires were held along with observations of the production to answer the questions. The result was an Overall Equipment Effectiveness of 46,44 % and needs and requirements from the organisation while digitally measuring in production. The outcome is a benchmark of the maintenance system and a scalable maintenance strategy with a holistic viewpoint. / Målet med det här examensarbetet är att presentera en underhållsstrategi för ett litet till medelstort bolag som genomgår en expansionsfas och samtidigt startar implementeringen av Totalt Produktivt Underhåll inom organisationen. Syftet är att hitta ett riktmärke och kunna guida underhållsarbetet i framtiden och under uppstarten av en underhållsorganisation. Det gjordes genom två frågeställningar; om vad Anläggningseffektivitets värdet i produktion är samt hur digital mätning av Anläggningseffektivitet i framtiden bör gå till. Både intervjuer och frågeformulär har använts för datainsamling samt observationer av produktion för att kunna fastställa svar till frågeställningarna. Resultatet är ett riktmärke av Anläggningseffektivitet på 46,44 % samt behov och önskemål från organisationen vid digital mätning i produktion. Utfallet är ett riktmärke för underhållssystemet och en skalbar underhållsstrategi med holistiskt perspektiv.

Power Holding Company of Nigeria (PHCN), responsible for generating, transmitting and distributing electricity in Nigeria is being faced with an apparent huge maintenance problem which seemingly contributes greatly to the power demand problem of the country. This apparent maintenance problem is investigated by surveying its root causes through interviews, questionnaires and data gathered from selected case studies. Questionnaires were used scientifically with a confidence level of 95% and interval of +-5% and +-4.4% to establish a high level of integrity on data gathered. Findings and deliverables are compared to South Africa’s power utility company Eskom for validation of the final deliverable. With the findings of this survey, the research problem was overcome by developing a new maintenance strategy and work authorization system for the company while making some recommendations on the training being given to its maintenance personnel. The New strategy called ‘Utility Availability Centered Maintenance Strategy’ or UACMS is presented in the form of a flow chart/ block diagram with its different sections fully explained. It mainly combines preventative, predictive and corrective maintenance strategies alongside other modern maintenance techniques. It’s all linked to a computer database support to ensure high effectiveness. Furthermore, the work authorization system called ‘Internal Task Authorization form’ serves to ensure responsibility in task execution within the company. During the course of this research, an excessive application of corrective maintenance strategy, lack of root cause analysis and unavailability of computer based applications were discovered in PHCN. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

Power Holding Company of Nigeria (PHCN), responsible for generating, transmitting and distributing electricity in Nigeria is being faced with an apparent huge maintenance problem which seemingly contributes greatly to the power demand problem of the country. This apparent maintenance problem is investigated by surveying its root causes through interviews, questionnaires and data gathered from selected case studies. Questionnaires were used scientifically with a confidence level of 95% and interval of +-5% and +-4.4% to establish a high level of integrity on data gathered. Findings and deliverables are compared to South Africa’s power utility company Eskom for validation of the final deliverable. With the findings of this survey, the research problem was overcome by developing a new maintenance strategy and work authorization system for the company while making some recommendations on the training being given to its maintenance personnel. The New strategy called ‘Utility Availability Centered Maintenance Strategy’ or UACMS is presented in the form of a flow chart/ block diagram with its different sections fully explained. It mainly combines preventative, predictive and corrective maintenance strategies alongside other modern maintenance techniques. It’s all linked to a computer database support to ensure high effectiveness. Furthermore, the work authorization system called ‘Internal Task Authorization form’ serves to ensure responsibility in task execution within the company. During the course of this research, an excessive application of corrective maintenance strategy, lack of root cause analysis and unavailability of computer based applications were discovered in PHCN. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

As a result of global competition, companies within the automotive industry are required to improve their production systems to achieve sustainable and competitive production. To attain operational excellence, companies have adopted concepts like lean and World Class Manufacturing (WCM). In order to deliver, companies need to increase the availability and reliability of production equipment. This demands focus on both operational and strategic maintenance, and efficient equipment acquisition and management. The main objective of this thesis is to identify processes and success factors that are necessary for improved maintenance performance. By conducting a case study and by performing a literature review, the following has been studied: 1) how companies within the automotive industry work with maintenance and maintenance strategies, 2) implementation of maintenance strategies, and 3) new acquisition and spare parts management for maintenance.  The results show that basic maintenance concepts and related terms are well defined in the literature. However, maintenance strategy is not unanimously defined. Results from the case study reveal that Professional Maintenance (PM) within WCM has been considered as a maintenance strategy. Furthermore, driving forces and obstacles for implementing maintenance strategies have been identified. The study also reveals that there is a strong link between maintenance performance, new acquisition and spare parts management. / Den globala konkurrensen inom fordonsindustrin, har medfört krav på företag att effektivisera sina produktionssystem för att åstadkomma en hållbar och konkurrenskraftig produktion. Detta har resulterat i arbete enligt koncept som lean och World Class Manufacturing (WCM).  För att kunna leverera behöver företag öka den tekniska tillgängligheten på utrustning. Detta i sin tur ställer ett ökat krav på både operativt och strategiskt arbete med underhåll, anskaffning och reservdelsstyrning. Målet med examensarbetet är att identifiera processer och faktorer som bidrar till ett förbättrat underhåll. Med hjälp av litteraturstudie och en fallstudie har följande studerats: 1) hur företag inom fordonsindustrin arbetar med underhåll och underhållsstrategier, 2) implementering av underhållsstrategier, och 3) nyanskaffning och reservdelsstyrning för underhåll. Resultat från litteraturstudier visar att det finns en enighet om att underhåll delas in i förebyggande och avhjälpande underhåll. Däremot, visar resultatet att det inte finns en enig definition av underhållsstrategi. Fallstudien visar att Professional Maintenance (PM) inom WCM betraktas som en underhållsstrategi. Som ett resultat har även ett antal drivkrafter och svårigheter som påverkar implementering av underhållsstrategier identifierats. Vidare visar resultatet att det finns ett starkt samband mellan underhåll, nyanskaffning och reservdelsstyrning.

M. Tech. (Department of Mechanical Engineering, Faculty of Engineering and Technology), Vaal University of Technology. / The subject of maintenance optimisation is not new, and many researchers have explored it. However, it is seen that one optimisation solution cannot be used in all industries. Each industry and equipment thereof are unique as the product streams differ, layouts and operation variables, to name a few. Though Turn-around management is the most used strategy in petrochemical industries. Equipment downtime remains the biggest challenge thus, the purpose of the study was to optimise the maintenance practices used on the critical electromechanical equipment in Sasol Synfuels Catalyst Preparation using both the Analytical Network and Analytical Hierarchy multi-decision approach. Data was collected from the SAP system database, of which the breakdown work orders was obtained from the period of January 2016 to June 2021. The data was collected for each 13 electromechanical equipment identified in the catalyst preparation unit. The applied maintenance strategies employed on the electromechanical equipment in the catalyst preparation unit was also analysed using the Meridium maintenance strategy software tool utilised in Sasol Synfuels. An analysis and identification of the critical equipment within the unit were obtained with the use of two different methods, namely the JADERI, (2019) and AFEFY, (2010) approaches. A theoretical distribution was drawn after that in order to assess the effectiveness of the current maintenance strategy compared to the identified key performance indicators. The theoretical distribution analysis was used to determine the plant utilisation, availability, and maintenance cost. The analytical network and hierarchy process application, and the super decision network model framework, were analysed to obtain the maintenance optimisation solution. Though the ANP and AHP approaches have different problem identification frameworks and cluster dependencies, it is seen that both methods portray more or less similar results. Both methods indicate that in order to achieve an optimised maintenance strategy within the catalyst preparation unit, condition-based maintenance strategy is the most weighed alternative node with 50% for optimal maintenance solution. The least most weighed alternative node is corrective maintenance, weighed at 7%. This is true as corrective maintenance is applied once a breakdown has occurred, of which the aim is to avoid unforeseen breakdowns. Fixed time maintenance is the second most weighed maintenance strategy with 30%, followed then by the operate to failure strategy at 13%. Considering that the operation to failure maintenance strategy is applied based on the consequence of failure and maintenance cost as well as mean time to repair, this is then concluded as practical as RCM priorities predictive and preventative strategies to be employed. It was drawn, for criteria nodes, that the ANP approach resulted in the environmental safety impact as the most important criteria to consider when applying the optimal maintenance strategy in the Sasol Synfuels Catalyst preparation unit. The environmental safety impact was rated at 0.33, followed by availability with a factor of 0.32. The least weighed criteria nodes are then the maintenance cost and MTTR, both with a factor of 0.17. This proves to true considering that the petrochemical industry is considered a high-risk industry as it processes and produces hazardous chemicals The AHP approach structure however, does not consider interdependencies through the criteria and alternative clusters thus the alternative weight could not be defined. The results obtained prove that the ANP approach is the most practical mutli criteria decision making method for maintenance optimisation compared to the AHP approach.

The electrical grid balances production capacity and demand in real-time. With an increased demand for renewable energy sources, challenges such as stability of the grid, the balance between generation and demand, and power quality occur. One way to deal with the variability is by introducing Battery Energy Storage System (BESS) to the electric grid. To ensure a stable connection, the BESS must be reliable, and much research has been carried out on the BESS reliability. However, the previous studies have mainly focused on the DC reliability of the system and little research has been conducted on the AC side of a BESS. This thesis aims to provide a reliability-based maintenance strategy for the AC-side of a BESS. First, the reliability index of each AC component is calculated with established models, and based on the results, the maintenance strategy is developed. It is shown that the load current and ambient temperature are the two main parameters that affect a BESS’s reliability. For longer periods of continuous operation, the reliability declines with time and the failure rate increases. The most suitable maintenance strategy is a combination of preventive and predictive. The frequency of the scheduled preventive maintenance differs between the AC components since the schedule is based on the results from individual reliability indices. The preventive maintenance uses the condition monitoring method to observe some key elements such as DC-bus neutral current and junction temperature. / Det elektriska distributionsnätet balanserar produktionskapacitet och efterfrågan i realtid. I samband med den ökade efterfrågan av förnyelsebara energikällor uppstår nya utmaningar, såsom nätstabilitet, balans mellan produktion och efterfrågan och kvaliteten. Ett sätt att hantera variationen är att introducera Batterienergilagringssystem (BESS) till distributionsnätet. För att säkerställa en stabil anslutning måste BESS vara tillförlitlig och mycket forskning har utförts kring BESS tillförlitlighet. Fokus från de tidigare studierna har dock främst varit på DC-sidan av systemet och nästintill ingen forskning har fokuserats på den AC-sidan och dess tillförlitlighet. Denna masteruppsats syftar till att tillhandahålla en tillförlitlighetsbaserad underhållsstrategi för AC-sidan av en BESS. Först beräknas tillförlitlighetsindexet för varje AC-komponent från etablerade modeller och den underhållsstrategin utvecklas senare baserats på resultaten från tillförlighetsindex. Det visar sig att strömmen och omgivningstemperaturen är de två huvudparametrarna som påverkar tillförlitligheten. Vid längre perioder av kontinuerlig drift minskar tillförlitligheten med tiden och felfrekvensen ökar. Den mest lämpliga underhållsstrategin är en kombination av förebyggande och förutsägande. Frekvensen av det schemalagda förebyggande underhållet skiljer sig mellan AC-komponenterna eftersom schemat är baserat på resultaten från individuella tillförlitlighetsindex. Det förebyggande underhållet använder tillståndsövervakningsmetoden för att observera några nyckelelement såsom likström och kopplingstemperatur.

fficient structures and a systematic way of working are required to maintain and keep an aging infrastructure of construction buildings to meet the requirements of road safety and function. Regular inspections and the right priorities regarding the need for operation and maintenance are an important prerequisite for long-term sustainable management and community building. This thesis aims to contribute to increased knowledge about municipal management of various types of construction buildings. By answering the three questions “How are municipal construction buildings managed?”, “What are the challenges for municipal managers?” and “Which maintenance strategies create the best conditions for ensuring maximum technical service life and thus a socio-economically sustainable development?”, the aim is investigate different structures and working methods to promote sustainable management by making the right priorities when there is a need for operation and maintenance. The methods chosen to produce this report are literature studies, interviews, email contact and meetings with a few different people in the public sector. Most of the report´s content is based on literature studies. Other methods that have been applied complement the literature study. The results showed that the majority of all municipal management of various types of construction buildings take place through the management system BaTMan with registered inspections and damages as a starting point for large and costly operation and maintenance measures. For ongoing operation and maintenance, other systems and tools are used as a complement to BaTMan.  The results also showed that there are a number of challenges for municipal managers who often face a rapid expansion development with many new buildings and ever-increasing number of inhabitants. Today, lack of communication and information between various municipal departments and administrations is a major problem when it comes to the construction of new construction buildings and the consequences these have for the operation and maintenance activities. Through increased cooperation across administrative boundaries, great coordination opportunities can be created to build more sustainably. From a socio-economic perspective, different maintenance measures can lead to different amounts of traffic disruption that can lead to costs for society. It is cheaper for society if the proportion of risk-reducing repairs is increased to recuse the need for urgent repairs. In addition to reduced costs, this could also lead to minor traffic disruptions.   The conclusion of the work is that today's and tomorrow's society is dependent on a well-unctioning infrastructure. Through a systematic approach with the right priorities,commitment and interest in efficient management, major socio-economic effects can be achieved. / Det krävs effektiva strukturer och ett systematiskt arbetssätt för att underhålla och sköta en åldrande infrastruktur av konstruktionsbyggnader för att uppfylla kraven på trafiksäkerhet och funktion. Regelbundna inspektioner och rätt prioriteringar när det gäller behov av drift och underhåll är en viktig förutsättning för ett långsiktigt hållbart förvaltarskap och samhällsbyggande. Detta examensarbete syftar till att bidra med ökad kunskap om kommunalt förvaltarskap av olika typer av konstruktionsbyggnader. Genom att besvara de tre frågeställningarna ”Hur förvaltas kommunala konstruktionsbyggnader?”, ”Vilka utmaningar finns för kommunala förvaltare?” och ”Vilka underhållsstrategier skapar bäst förutsättningar för att säkerställa maximal teknisk livslängd och därmed en samhällsekonomisk hållbar utveckling?” är målet att utreda olika strukturer och arbetssätt för att främja en hållbar förvaltning genom att rätt prioriteringar görs vid behov av drift och underhåll. De metoder som valts för att framställa denna rapport är litteraturstudier, intervjuer, mailkontakt och möten med ett antal olika personer inom offentlig sektor. Största delen av rapportens innehåll baseras på litteraturstudier. Andra metoder som har tillämpats kompletterar litteraturstudien.  esultaten visade att majoriteten av all kommunal förvaltning av olika typer av konstruktionsbyggnader sker genom förvaltningssystemet BaTMan med registrerade inspektioner och skador som utgångspunkt för stora och kostsamma drift- och underhållsåtgärder. För löpande drift- och underhåll används andra system och verktyg som ett komplement till BaTMan. Av resultaten framkom även att det finns ett antal utmaningar för kommunala förvaltare som ofta står inför en snabb expansion utveckling med många nya byggnationer och ständigt ökande invånarantal. Idag utgör bristande kommunikation och information mellan olika kommunala avdelningar och förvaltningar ett stort problem när det gäller byggnation av nya konstruktionsbyggnader och de konsekvenser som dessa medför för drift- och underhållsverksamheten. Genom ökat samarbete över förvaltningsgränserna kan stora samordningsmöjligheter skapas för att bygga mer hållbart.  Ur ett samhällsekonomiskt perspektiv kan olika underhållsåtgärder medföra olika mycket trafikstörningar som kan leda till kostnader för samhället. Det är billigare för samhället om andelen riskreducerande reparationer ökas för att minska behoven av akuta reparationer. Utöver minskade kostnader skulle detta även kunna leda till mindre trafikstörningar.  Slutsatsen av arbetet är att dagens och framtidens samhälle är beroende av ett välfungerande infrastruktur. Genom ett systematiskt arbetssätt med rätt prioriteringar, engagemang och intresse för effektiv förvaltning kan stora samhällsekonomiska effekter uppnås.

L'optimisation de stratégies de maintenance est un sujet primordial pour un grand nombre d'industriels. Il s'agit d'établir un plan de maintenance qui garantisse des niveaux de sécurité, de sûreté et de fiabilité élevé avec un coût minimum et respectant d'éventuelles contraintes. Le nombre de travaux grandissant sur l'optimisation de paramètres de maintenance et notamment sur la planification d'actions préventives de maintenance souligne l'intérêt de ce problème. Un grand nombre d'études sur la maintenance repose sur une modélisation du processus de dégradation du système étudié. Les Modèles Graphiques Probabilistes (MGP) et particulièrement les MGP Markoviens (MGPM) fournissent un cadre de travail pour la modélisation de processus stochastiques complexes. Le problème de ce type d'approche est que la qualité des résultats est dépendante de celle du modèle. De plus, les paramètres du système considéré peuvent évoluer au cours du temps. Cette évolution est généralement la conséquence d'un changement de fournisseur pour les pièces de remplacement ou d'un changement de paramètres d'exploitation. Cette thèse aborde le problème d'adaptation dynamique d'une stratégie de maintenance face à un système dont les paramètres changent. La méthodologie proposée repose sur des algorithmes de détection de changement dans un flux de données séquentielles et sur une nouvelle méthode d'inférence probabiliste spécifique aux réseaux bayésiens dynamiques. D'autre part, les algorithmes proposés dans cette thèse sont mis en place dans le cadre d'un projet d'étude avec Bombardier Transport. L'étude porte sur la maintenance du système d'accès voyageurs d'une nouvelle automotrice destiné à une exploitation sur le réseau ferré d'Ile-de-France. L'objectif général est de garantir des niveaux de sécurité et de fiabilité importants au cours de l'exploitation du train / The optimization of maintenance strategies is a major issue for many industrial applications. It involves establishing a maintenance plan that ensures security levels, security and high reliability with minimal cost and respecting any constraints. The increasing number of works on optimization of maintenance parameters in particular in scheduling preventive maintenance action underlines the importance of this issue. A large number of studies on maintenance are based on a modeling of the degradation of the system studied. Probabilistic Models Graphics (PGM) and especially Markovian PGM (M-PGM) provide a framework for modeling complex stochastic processes. The issue with this approach is that the quality of the results is dependent on the model. More system parameters considered may change over time. This change is usually the result of a change of supplier for replacement parts or a change in operating parameters. This thesis deals with the issue of dynamic adaptation of a maintenance strategy, with a system whose parameters change. The proposed methodology is based on change detection algorithms in a stream of sequential data and a new method for probabilistic inference specific to the dynamic Bayesian networks. Furthermore, the algorithms proposed in this thesis are implemented in the framework of a research project with Bombardier Transportation. The study focuses on the maintenance of the access system of a new automotive designed to operate on the rail network in Ile-de-France. The overall objective is to ensure a high level of safety and reliability during train operation