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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Monitoring railway traffic loads using bridge weight-in-motion

Liljencrantz, Axel January 2007 (has links)
QC 20101111

Implementing FMEA for Scaling Start-ups : A Case Study of Adaptation for Overcoming Novel Technology Challenges

Kinisjärvi, Robert January 2023 (has links)
A start-up cannot simply be considered a smaller version of an established company. They often rely on short and informal development processes because they lack data and experience from implementing similar projects in the past. These factors are among those that lead to lower success in organizational performance and new product launches. The NPD process is well researched, but these studies are often on larger companies, and the applicability for start-ups is highly questionable. One of these NPD tools is the FMEA. FMEA has been proven and established for decades in various industries. However, these success scenarios often depend on sufficient resources in terms of staff and project budget. Start-ups often lack the resources to deal with major NPD project failures, which can be disastrous for their survival in their market. Despite the innovative benefits and economic growth that start-ups contribute to when they are successful with their NPD projects, there is little research on how established tools for large companies should be adapted. Therefore, these research questions were formulated to fill the gap in the current FMEA method: RQ1: What are the challenges for start-ups when implementing FMEA? RQ2: How can FMEA implementation be adapted for start-ups overcoming novel technology challenges?  The study consisted of a literature review and a case study. The literature review examined the key factors for FMEA implementation and the differences between start-ups and established companies. The challenges for start-ups implementing FMEA were the central question of the literature review. The case study was conducted in a start-up company. An adapted FMEA method and template were created there. A workshop and ten interviews were held with a variety of representatives. The results show that the biggest challenge for start-ups implementing FMEA is that it is too complex, unclear, and often too extensive. This can be changed by simplifying the FMEA, focusing on the critical risks, and ensuring that the sessions are not too long. The proposed FMEA method is easier to use with a simplified risk assessment and fewer columns. It was found that it also is equally important to train users, hold short meetings, and limit the size of each FMEA session.

Engineering rubber bushing stiffness formulas including dynamic amplitude dependence

Garcia, Maria-José January 2006 (has links)
Engineering design models for the torsion and axial dynamic stiffness of carbon black filled rubber bushings in the frequency domain including amplitude dependence are presented. They are founded on a developed material model which is the result of applying a separable elastic, viscoelastic and friction rubber component model to the material level. Moreover, the rubber model is applied to equivalent strains of the strain states inside the torsion or axial deformed bushing previously obtained by the classical linear theory of elasticity, thus yielding equivalent shear moduli which are inserted into analytical formulas for the stiffness. Therefore, unlike other simplified approaches, this procedure includes the Fletcher-Gent effect inside the bushing due to non-homogeneous strain states. The models are implemented in Matlab®. In addition, an experimental verification is carried out on a commercially available bushing thus confirming the accuracy of these models which become a fast engineering tool to design the most suitable rubber bushing to fulfil user requirements. Finally, they can be easily employed in multi-body and finite element simulations / QC 20101112

Processförbättring vid tillverkning av konstruktionskeramer

Garvare, Rickard January 1998 (has links)
This thesis is about implementing Design of Experiments in enterprises manufacturing high performance ceramics. The manufacturing of ceramics is a complex process which involves problems with variation in product properties and in process performance. Every system in operation generates information that can be used to improve it. To be able to improve, measurements must be made and recorded data must be transformed into information. Design of Experiments is about performing tests using a minimum of resources to receive a maximum of information about a process or a system. Today most of the development of processes and products is done supported by expensive, and often misleading, one-factor-at-a-time experiments. To examine the possibilities of facilitating implementation of Design of Experiments, case-studies of two Swedish manufacturers of high performance ceramics were carried out. A model of implementing Design of Experiments is presented based on theory and the case-studies. The proposed model consists of three major phases: 1.Planning and education. 2.Pilot project with new ways of working. 3.Assessment, maintenance and improvement. Design of Experiments appears to be a well suited technique for structuring the development of manufacturing high performance ceramics. The implementation of Design of Experiments could be facilitated by long-term planning for process improvement. To make assessment and evaluation possible, process performance should be documented not only after but also before an implementation takes place. Both knowledge about statistics and knowledge about the studied processes should be present in the teams carrying out experiments. / <p>Godkänd; 1998; 20070404 (ysko)</p>

Squat Detection in Railway Switches &amp; Crossings Using Point Machine Vibration

Zuo, Yang January 2022 (has links)
Railway switches and crossings (S&amp;Cs) are among the most important high-value components in a railway network and a single failure of such an asset could result in severe network disturbance, huge economical loss, and even severe accidents. Therefore, potential defects need to be detected at an early stage and the status of the S&amp;C must be monitored to prevent such consequences. One type of defect that can occur is called a squat. A squat is a local defect like a dent or an open pit in the rail surface. In this thesis, a testbed including a full-scale S&amp;C and a bogie wagon was studied. Vibrations were measured for different squat sizes by an accelerometer mounted at the point machine, while a boggy was travelling along the S&amp;C. A method of processing the vibration data and the speed data is proposed to investigate the feasibility of detecting and quantifying the severity of a squat. A group of features were extracted to apply isolation forest to generate anomaly scores to estimate the health status of the S&amp;C. One key technology applied is wavelet denoising. The study shows that it is possible to monitor the development of the squat size introduced in the test bed by measuring point machine vibrations. The relationships between the normalised peak-to-peak amplitude of the vibration signal and the squat depth were estimated. The results also show that the proposed method is effective and can produce anomaly scores that can indicate the general health status of an S&amp;C regarding squat defects.

Optimering av rotordrift för värmeväxlare / Optimering av rotordrift för värmeväxlare

Holländer, Anton January 2023 (has links)
No description available.

Models and meaning : on management models and systems of meaning when implementing change

Hallencreutz, Jacob January 2009 (has links)
Change has become a vital business partner for many organizations. Survival of most organizations depends on their ability to implement adequate changes to support the organization. This thesis deals with questions about measurement systems, process based system models and organizational change with a specific focus on implementation challenges.The purpose of this research is to explore the relationship between management models and systems of meaning in change implementation processes and hopefully contribute to the understanding of organizational change through empirical research based on practical experience. To be able to accomplish the purpose, the following research questions have been formulated:1. How can a measurement system act as a driver for organizational change?2. How can business excellence models be designed to focus on stakeholder demands and organizational sustainability?3. How can the implementation of a process based system model help organizations to accelerate change?4. What is the role of management models when implementing change?The theoretical frame of reference is focusing on aspects of organizational change and systems thinking. Three papers, based on three case studies, are appended to the thesis. The first study deals with performance management systems, the second study is assessing the use of business excellence models and the third study is tracking the implementation of a process based system model in three organizations. The indications are that there could be easy gains to be realized in focusing on the measurement system and by adopting a process based approach focused on stakeholder satisfaction. Study 2 indicates that successful use of business excellence models requires effective deployment of basic quality-related values within the organization. However, organizations considering the use of BEMs need to have strong long-term commitment. The results from study 3 indicate that implementation of a system model focusing on processes, resources and a multiple stakeholder perspective aids management to accelerate change. The results also indicate that there are other more crucial success factors than the model as such. Key success factors seem to be: Strategic clarity, management decisiveness and perseverance. Finally, the network of gaps between change theory (meaning different theoretical and methodological considerations written in textbooks and articles) and change practice (meaning organizations trying to accomplish things based on interpreting textbooks and articles) is discussed. / Modeller och meningsskapande : om ledningsmodeller och meningssystem vid genomförande av förändringFör många organisationer har förändring blivit en viktig följeslagare. De flesta organisationers överlevnad är beroende av förmågan att genomföra nödvändiga förändringar. Denna uppsats behandlar frågor om organisatorisk förändring med särskilt fokus på mätsystem, processbaserade systemmodeller och implementeringsutmaningar.Syftet med de studier som presenteras i denna uppsats är att utforska relationen mellan ledningsmodeller och meningssystem vid genomförande av förändring och förhoppningsvis, med hjälp av empiriska studier baserade på praktisk erfarenhet, bidra till ökad förståelse för området organisatorisk förändring. För att uppnå detta syfte har fyra forskningsfrågor formulerats:1. Hur kan ett mätsystem fungera som drivkraft vid organisatorisk förändring?2. Hur kan "business excellence"-modeller utformas för fokus på intressenter ochorganisatorisk hållbarhet?3. Hur kan implementeringen av en processbaserad systemmodell hjälpa organisationeratt accelerera förändring?4. Vilken roll har ledningsmodeller vid genomförande av förändring?Den teoretiska referensramen i denna uppsats fokuserar på olika aspekter av organisatorisk förändring och systemtänkande. Tre artiklar, baserade på tre studier, ingår i uppsatsen. Den första studien handlar om mätsystem, den andra studien utvärderar "business excellence"-modeller och den tredje studien följer implementeringen av en processbaserad systemmodell i tre organisationer.Resultaten från studie 1 indikerar att det finns enkla vinster att nå genom att fokusera på organisationers mätsystem samt införandet av ett processynsätt med fokus på intressentnytta. Den andra studien ger bilden att det krävs inarbetade kvalitetsorienterade värderingar för att en organisation ska kunna använda "business excellence"-modeller framgångsrikt. Organisationer som överväger att använda dessa modeller måste även se det som ett långsiktigt åtagande. Resultaten från studie 3 indikerar att införandet av en systemmodell som fokuserar på processer, resurser och intressentperspektiv hjälper ledningen att accelerera förändring. Resultaten tyder också på att det finns andra mer kritiska framgångsmönster än användandet av en viss modell. Nyckelfaktorer tycks vara: strategisk tydlighet, beslutsamhet hos högsta ledningen samt uthållighet.Slutligen diskuteras nätverket av gap mellan förändringsteorier (i betydelsen teoretiska aspekter på förändring framlagda i böcker och artiklar) och förändringspraktiker (i betydelsen organisationer som försöker åstadkomma praktisk förändring genom att tolka teoretiska aspekter framlagda i böcker och artiklar).

Exploring a project-based organization through the eyes of continuous improvement and learning

Sundqvist, Erik January 2015 (has links)
The concepts of continuous improvement (CI) and learning are advocated in project management (PM) literature and standards, as suitable concepts to adopt when managing projects. CI can be described as philosophy in which all members of an organization work together to achieve sustained and incremental improvements.Learning can in turn be divided into the learning organization, focusing oncharacteristics that allow an organization to learn, and organizational learning,focusing on how learning is achieved in an organizational context. How big of a part projects play in organizations can differ, from scarce occurrence to being the dominant way of working. Organizations that solely carry out projects can bedescribed as project-based organizations (PBOs). This study explores the concepts of CI and learning in the context of a project-based organization. The reason for doing this is that little information has been found on how CI and learning should be achieved and sustained in a PM context, although being described as important concepts in PM.A longitudinal exploratory case study was performed, at the Projects department at Luossavaara-Kiirunavaara AB, in order to understand how the concepts of CI and learning could be applied in a PBO. Several data collection methods have been applied in order to achieve triangulation. A qualitative approach was used in order to understand the specific characteristics associated with operating as a PBO, and thus affecting if and how CI and learning could be applied. The research process, whichdescribes the case study in chronological order, and display findings as they emerged, is given a fair amount of room in the thesis, in order to allow the reader to both scrutinize the study, and reach conclusions of her own.The findings indicate that no aspects of operating as a PBO counteract the potential of achieving CI and learning, but that awareness has to be raised regarding the challenges that come with it. CI is described as attractive due to a low-cost approach, and low entry barriers. This description is however based on applying CI in repetitive task environments (e.g. manufacturing industry), not the non-repetitive task environment that characterizes operating as a PBO. If CI is to be achieved in a PBO it is likely that both the PBO and the concept of CI has to be adjusted to one another, to a much greater extent than is described in the CI literature. The current approaches to learning in PBOs seem to be based on a hard approach, trying to capture and disseminate learning throughout the organization. However, this study indicates that this way of working falls short, and suggests that a softer approach might be needed in order to achieve organizational learning in PBOs

Experiments and Capability Analysis in Process Industry / Experiment och duglighetanalys i processindustrin

Lundkvist, Peder January 2012 (has links)
The existence of variation has been a major problem in industry since the industrial revolution. Hence, many organizations try to find strategies to master and reduce the variation. Statistical analysis, such as process capability analysis and Design of Experiments (DoE), often plays an important role in such a strategy. Process capability analysis can determine how the process performs relative to its requirements or specifications, where an important part is the use of process capability indices. DoE includes powerful methods, such as factorial designs, which helps experimenters to maximize the information output from conducted experiments and minimize the experimental work required to reach statistically significant results.Continuous processes, frequently found in the process industry, highlight special issues that are typically not addressed in the DoE literature, for example, autocorrelation and dynamics. The overall purpose of this research is to contribute to an increased knowledge of analyzing DoE and capability in process industry, which is achieved through simulations and case studies of real industrial processes. This research focus on developing analysis procedures adapted for experiments and comparing decision methods for capability analysis in process industry.The results of this research are presented in three appended papers. Paper A shows how the use of a two-level factorial experiment can be used to identifying factors that affect the depth and variation of the oscillation mark that arises from the steel casting process. Four factors were studied; stroke length of the mold, oscillation frequency, motion pattern of the mold (sinus factor), and casting speed. The ANOVA analysis turned out to be problematic because of a non- orthogonal experimental design due to loss of experimental runs. Nevertheless, no earlier studies where found that shows how the sinus factor is changed in combination with the oscillation frequency so that the interaction effect could be studied. Paper B develops a method to analyze factorial experiments, affected by process interruptions and loss of experimental runs, by using time series analysis. Paper C compares four different methods for capability analysis, when data are autocorrelated, through simulations and case study of a real industrial process. In summary, it is hard to recommend one single method that works well in all situations. However, two methods appeared to be better than the others. Keywords: Process industry, Continuous processes, Autocorrelation, Design of Experiments, Process capability, Time series analysis. / Förekomsten av variation i tillverkningsprocesser har varit ett problem redan sedan den industriella revolutionen. Därför har många organisationer försökt hitta en strategi för att hantera och reducera variationen. Statistiska metoder som duglighetsanalys och försöksplanering spelar ofta en viktig roll i dessa sammanhang. Duglighetsanalys bedömer hur processen presterar i relation till dess krav eller specifikationer, där en viktig del är användningen av duglighetsindex. Försöksplanering omfattar kraftfulla metoder, exempelvis faktorförsök, för att hjälpa den som utför experiment att maximera informationsutbytet vid experiment och samtidigt minimera de resurser som krävs för att nå statistiskt säkerställda resultat.Kontinuerliga processer, vilka är frekvent förekommande i processindustrin, ger upphov till speciella problem vid experiment som normalt inte behandlas i litteraturen, exempelvis autokorrelation och dynamik. Det övergripande syftet med forskningen i denna avhandling är att bidra till en ökad kunskap om analysen av försöksplanering och duglighet i process industri, vilket uppnås genom simuleringar och fallstudier av verkliga industriella processer.Denna forskning fokuserar på att föreslå och utveckla analysmetoder anpassade för experiment samt att jämföra olika beslutsmetoder för duglighetsanalys i industriella processer.Resultaten av forskningen presenteras i tre bifogade artiklar. Artikel A visar hur ett två-nivåers faktorförsök kan användas för att identifiera de faktorer som påverkar oscillationsmärkesdjupet som uppstår från stålstränggjutnings¬processen. Fyra faktorer studerades; slaglängden av gjutform, svängnings¬frekvensen, rörelsemönstret av gjutform (sinusfaktor) och gjuthastigheten. ANOVA analys visade sig vara problematiskt eftersom försöksdesignen inte var ortogonala på grund av förlorade försöksomgångar. Trots det har inga tidigare studier hittats som visar hur sinusfaktorn ändras i kombination med svängnings¬frekvensen så att samspelseffekten kan studeras. Artikel B utvecklar en metod för att analysera faktorförsök, påverkat av processavbrott och förlust av experimentomgångar, baserat på tidsserieanalys. Artikel C jämför fyra olika metoder för duglighetsanalys, när data är autokorrelerad, genom simuleringar och fallstudie av en faktisk industriell process. Sammanfattningsvis är det svårt att rekommendera en metod som fungerar bra i alla situationer. Resultaten pekar på att två metoder är bättre än de andra.

Kartläggning och jämförelse av arbetssätt att hantera kvalitetsbristkostnader i logistikprocessen / Mapping and comparison of working methods to handle cost of poor quality in the logistics process

Hermansson, Joel, Gottschalk, Max January 2017 (has links)
This bachelor thesis has been done in cooperation with IKEA of Sweden in Älmhult. It is about a mapping and comparison study of how different companies handle their cost of poor quality (COPQ) in their logistics processes. In this study, we have collaborated with Electrolux, Gekås and Rusta. IKEA has a high COPQ, this means when poor quality occurs in their processes. This has attracted much attention in recent years and there is room for improvement. The part of the value chain chosen in this project is the logistics process. The purpose of this bachelor thesis is to map IKEA´s logistics process, then compare IKEA´s way of working with other companies through a benchmarking study and finally come up with areas for improvement. This gave the questions: How does IKEA's operate in their logistics process today and handle their cost of poor quality? How do our other partners operate and handle their logistics processes and cost of poor quality? What are the similarities and differences between the different companies? To find out how IKEA operates in their logistics process today, it was decided to make a corporate visit to one of IKEA's CDC:s. Here, a questionnaire has been used to get the information that was needed. Later this questionnaire formed the basis for the survey that was used to gather information from our other partners. To gather information from our partners, we have used benchmarking. This was done to see how our other partner organizations operate today and how they work accordingly to this study. The first step of the benchmarking, was to send out the survey to our partners. Later we followed up with personal interviews and visits. The collected data from the different companies formed the basis of the status report of them all. In the analysis, IKEA has been compared to each of our different partners and a summary of the analysis has been made. With the analysis finished, it has been clear that IKEA has some problems in their logistic process and that the cost of poor quality can decrease. This gave us some areas that IKEA can make improvements in. After that conclusion, forklift damages and packaging design are two areas that IKEA can make big improvements in. / Detta examensarbete har gjorts tillsammans med IKEA of Sweden i Älmhult. Det handlarom en kartläggning och jämförelse av hur olika företag hanterar sinakvalitetsbristkostnader inom logistikprocessen. Våra samarbetspartners i dettaarbetet är Electrolux, Gekås och Rusta

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