With increasing awareness that maintenance not only ensures safety and track performance, but also creates additional value in the business process; many infrastructure managers and owners are treating maintenance as an integral part of the business process. This is also true for the Banverket (Swedish National Rail Administration). One key issue for Banverket is to verify that the undertaken maintenance activities provides expected results, measured through maintenance performance indicators (MPI) related to technical, economical, and organizational issues. It is also necessary to classify the degree of effect for every single MPI, i.e. to create a logical cause-and-effect structure. The main purpose of this research work is to identify and study the existing operation and maintenance performance indicators related to railway infrastructure, their application in short term and long-term perspective to analyse their usefulness for operation and maintenance planning of the railway infrastructure. Furthermore, the study is to find a structured, reliable, and cost effective method using maintenance performance indicators (MPI) such as OEE-values to facilitate the operation and maintenance decision making process both in short term and long term perspective for the railway infrastructure management. A study at Banverket shows that 10 MPIs out of 17 identified ones are in use, where eight of them match the MPIs identified through the documents and two additional ones identified through interviews. Two conducted case studies at Banverket and Jernbaneverket, the Norwegian rail administration, shows that it is possible to quantify and benchmark MPIs between different countries. The comparison from the Iron Ore Line between Kiruna and Narvik indicated more or less the same rail and track related maintenance costs per track kilometre in Norway as in Sweden. The overhead cost per track kilometre results in 12 times higher costs for Jernbaneverket due to different track length in Norway and Sweden, though the number of employees in the infrastructure manager organization work force was the same in both countries. A case study evaluating technical and financial aspects of grinding campaigns on the track section between Kiruna and Riksgränsen shows that the grinding campaign postpone major rail replacements activities into the future. The yearly cost for grinding and renewal is an example of an aggregated MPI that can be used for future follow-ups and benchmarking. The grinding campaign itself seems not to affect the total system in a negative way. One important issue for the infrastructure manager is to focus on the overall railway infrastructure effectiveness. A model for calculating the overall railway infrastructure effectiveness (ORIE) is presented in this thesis. Performed case studies on three track sections shows similar ORIE figures that are significantly higher than the industry OEE, which is required for a punctual railway transportation system. The study indicates that ORIE must be calculated on a monthly basis. The findings of the ORIE and calculation are 89.7 - 100% ORIE values. The findings indicate that ORIE can be used as a key performance indicator by the railway infrastructure manager. It is also visualized that ORIE can provide important input and support in decision making for the infrastructure managers. A railway infrastructure maintenance link and effect model (LinkEM), that supports the overall objectives and focuses on critical strategic areas determined by the nature of the railway industry and public requirements and regulations is suggested. To conclude, in this research study relevant MPIs for effective management of operation and maintenance of the railway infrastructure are identified and analyzed. Further, models like LinkEM and ORIE are suggested for the railway infrastructure managers to facilitate in the decision-making. / Infrastrukturförvaltare av järnväg ser idag underhåll som en värdeskapande och integrerad del av hela förvaltningsverksamheten för att uppfylla kundernas krav och förväntningar. En central uppgift för Banverket är att verifiera att genomförda underhållsåtgärder ger önskat resultat ur tekniska, ekonomiska och organisatoriska perspektiv. Ett sätt att mäta detta är att använda underhållsrelaterade indikatorer (MPIs, maintenance performance indicators). Det är därför viktigt att dessa indikatorer förmår koppla och visa effekter av genomförda underhållsaktiviteter, dvs. förmår visa underhållsrelaterade orsak-verkansamband.En studie genomförd på Banverket visar att utav 17 identifierade MPIs så används 10 stycken. Åtta av dessa är identifierade i Banverkets egna dokument medan de två övriga är identifierade genom intervjuer. Två genomförda studier på Banverket och Jernbaneverket visar att det är möjligt att kvantifiera och jämföra MPIs mellan olika länder med hjälp utav benchmarking. Jämförelsen visar att underhållskostnaderna per spårmeter är ungefärligen lika stora på svensk och norsk sida för Malmbanan. En liknande jämförelse av overheadkostnaderna visar att kostnaderna på den norska sidan är ungefär 12 gånger högre per spårmeter räknat. En jämförelse av organisationernas storlek till antalet anställda visar dock att de är ungefärligen jämstora. En teknisk och ekonomisk utvärdering av genomförda rälsslipningskampanjer på sträckan mellan Kiruna och Riksgränsen visar att rälsslipning kan fördröja behovet av utbyte av räl. Den årliga kostnaden för rälsbyte är ett exempel på MPIs som kan användas för uppföljning och benchmarking. Genomförda rälsslipningskampanjer ser inte ut att påverka järnvägssystemet som helhet på något negativt sätt. En viktig fråga för infrastrukturförvaltare av järnväg är att kunna mäta järnvägssystemets effektivitet. En modell för att kunna mäta just detta presenteras i denna avhandling, dvs en så kallad ORIE-modell (overall railway infrastructure effectiveness eller infrastruktureffektivitet för järnväg) Genomförda studier och simulering på bandelsnivå visar på höga och jämförbara ORIE-värden för de olika bandelarna, vilka för övrigt är påtagligt högre än för motsvarande OEE-värden för exempelvis tillverkande industri. Studien påvisar att ORIE-värdena bör beräknas per månad och att de kan användas som MPIs. Resultaten visar på ORIE-värden mellan 89,7 - 100 %. ORIE-värden kan därmed utgöra ett bra beslutsstöd för järnvägens infrastrukturförvaltare. Ett förslag på en länk- och effektmodell för järnvägsinfrastruktur vilken stödjer övergripande mål för verksamheten och som fokuserar på strategiska områden utifrån järnvägens förutsättningar presenteras i denna avhandling. Sammanfattningsvis så har denna studie identifierat ett antal MPIs som används av infrastrukturförvaltare av järnväg. Koncept och modeller såsom LinkEM, ORIE och benchmarking har applicerats på och genererat resultat användbara för infrastrukturförvaltare av järnväg. / Godkänd; 2008; 20080416 (ysko)

Reliability prediction of the electronic components used in industrial safety systems requires high accuracy and compatibility with the working environment. The traditional reliability prediction methods that draw on standard handbooks such as MIL-HDBK 217F, Telcordia, PRISM etc., are not appropriate to determine the reliability indices of these components. For one thing, technology is constantly advancing; for another, the empirical data do not always match the actual working environment.The newest reliability prediction methodology, the physics-of-failure (PoF), emphasizes the root cause of failure, failure analysis, and failure mechanisms based on the analysis of parameter characteristics. It involves a focused examination of failure point locations, considering the fabrication technology, process, materials and circuit layout obtained from the manufacturer. This methodology is capable of providing recommendations for the increased reliability of components using intuitive analysis.However, there is a limitation: it is sometimes difficult to obtain manufacturer’s details for failure analysis and quality information. Several statistical and probability modeling methods can be performed on the experimental data of these components to measure the time to failure. These experiments can be conducted using the accelerated-testing of dominant stress parameters such as Voltage, Current, Temperature, Radiation etc.In this thesis, the combination of qualitative data from PoF approach and quantitative data from the statistical analysis is used to create a modified physics-of-failure approach. This methodology overcomes the limitations of the standard PoF approach as it involves detailed analysis of stress factors, data modeling and prediction. A decision support system is created to select the best option from failure data models, failure mechanisms, failure criteria and other factors to ensure a growth in reliability.In this study, the critical electronic components used in certain safety systems from different technologies are chosen for reliability prediction: Optocoupler, Constant Fraction Discriminator, BJT Transistor, Voltage Comparator, Voltage Follower and Instrumentation amplifier. The study finds that the modified physics-of-failure methodology provides more accurate reliability indices than the traditional approaches using field data. Stress based degradation models are developed for each of the components. The modified PoF models developed using Response Surface Regression and Support Vector Machine (SVM) show better performance. / Godkänd; 2013; 20130813 (aditha); Tillkännagivande disputation 2013-08-23 Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Adithya Thaduri Ämne: Drift och underhållsteknik/Operation and Maintenance Avhandling: Physics-of-Failure Based Performance Modeling of Critical Electronic Components Opponent: Professor Hoang Pham, Dept of Industrial and Systems Engineering, Rutgers, The State University of New Jersey, USA Ordförande: Professor Uday Kumar, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Torsdag den 12 september 2013, kl 10.00 Plats: F1031, Luleå tekniska universitet

The railway is an important mode of transport, due to its environmental friendliness, high safety level, and low energy consumption combined with a high transport capacity, among other factors. The Swedish railway network is old, there has been almost no expansion of the network during the past few decades, and more traffic is expected. Therefore, there is currently a demand for more track capacity and, in the short term, the existing network is expected to deliver the increased capacity. The railway operators in the network have a large impact on train delays, and wheel failures are one large contributor of delays. Delays destroy capacity and, therefore, capacityconsuming failures, such as abnormal wheels, need to be minimised. This can be achieved by using appropriate condition monitoring for the wheels on the track to find potential capacity consumers before failures happen. Therefore, the condition of the wheel-rail interface is important, since the state of the wheel influences that of the rail and vice versa. The monitoring of rail profiles is already being performed, but the monitoring of wheel profiles is still in the development phase. This thesis treats the applications and performance assessment of a wheel profile measurement system (WPMS), and presents case studies focusing on its system and measurement performance. The proposed applications concern how the information from the WPMS can be integrated with information from other data sources and with physical models to obtain a true current picture of the wheel behaviour. The thesis investigates the measurement performance of the WPMS by using a paired T-test and a number of quality measures, e.g. the reproducibility and repeatability, the precision-to-tolerance ratio and the signal-to-noise ratio. In conclusion, this thesis shows that the WPMS works well with an expected level of reliability in a harsh climate with respect to its measurement and system performance. By combining other data with the data from the WPMS, potentially abnormal wheels can be found in an early stage if the proposed new maintenance limit for the wheel parameter of the flange height is implemented. Furthermore, through adding a physical model to the process, the real contact condition of the actual wheel-rail interface can be evaluated and measurement deviations can be found. However, the wheel parameters, as well as the entire profile, need a high measurement quality with little variation, which seems to be an issue with respect to the measurement performance when advanced calculations are to be done. Therefore, a new approach for evaluating measurement performance has been developed using established statistical tools and quality measures with predefined acceptance limits; with the help of this approach, one can differentiate between the variation in the measurements originating in the different measurement units and the variation originating in the wheels. This new approach can be applied to judge the measurement performance of wheel profile condition-monitoring systems, and can also be implemented for other condition-monitoring systems to evaluate their measurement performance. Finally, this approach promotes the development of a condition-based maintenance policy by providing more reliable information for maintenance decision makers.

The mining production in Kiruna is heading towards larger depth and it is necessary to prepare for the next generation of underground facilities and new mining methods below the current main level. An important issue is the increasing rock stresses, which follows the ever-increasing depth of mining. This may result in instability of drifts, ramps, shaft and other facilities. The objective of this thesis is to clarify the stress situation in the mine and to state a relationship that could be used for rock mechanical analysis. The first part of the thesis is an appraisal of the results from the rock stress measurements carried out during the 1980's and 1990's. The measured state of stress shows a large variation, which depends on the influence of the mining production, measuring errors, and the heterogeneous nature of the rock mass. Even though, the stress measurements clearly affected by the mining production is sorted out, the variation remains. This means that the stress state in Kiirunavaara is still difficult to interpret. In order to increase the understanding of the natural variation, a literature review and analyses of the stress distribution in the rock mass is given. Because of this uncertainty, the second part presents another approach of handling the problems with the large scatter in the measured state of stress. By doing conceptual numerical analyses and probabilistic sensitivity analyses of underground constructions, the parameters affecting the behavior of the rock mass are studied. The analyses shows that the significance of the variation of the stress state is less than the significance of many other parameters like the stiffness and the strength of the rock mass. The recommendations is therefore, that a geomechanical model of the mine should be developed including for instance, the spatial variation of parameters like Young's modulus and strength of intact rock and joint parameters like number of joint sets, orientation, frequency and filling material. / <p>Godkänd; 2003; 20070218 (ysko)</p>

Open pit mines constitute more than half of global minerals production. Yet most of the large, high-grade, and close to the surface deposits have been depleted or are currently in production. Besides, volatility in commodity prices and stringent environmental regulations limit the up-scaling expansions in large open pits. Consequently, the mines are determined to increase their operational efficiency in order to thrive. This has recently led to major metallurgical improvements in the processing of ores; whereas the improvements in mining of the said ores are relatively overdue in terms of efficiency and technological advancement. This thesis concentrates on the mining activities and their efficiency in open pits with a focus on drilling, blasting, loading, and crushing. As all of these tasks revolve around the fragmentation of run-of-mine ore, their relationships and efficiencies are explored within the context of fragmentation. Fragmentation is a result of complex interactions between rockmass, blasting geometry, explosive, and timing sequence of blast holes. The influence of rockmass and timing sequence on fragmentation and efficiency are explored, as well as the target fragmentation for efficient loading and crushing. Moreover, the techniques for measuring fragmentation are evaluated as to whether they can benefit mines in terms of efficiency. As the circumstances in open pits are essentially site-specific, these issues are addressed as a case study of the Aitik mine in Sweden. The research comprised four elements. First, the influence of rockmass fractures on blast results and downstream efficiency was evaluated via full-scale field trials. The fractures in and around the case study mine were mapped using a photogrammetric technique and six production blasts were adapted to the major fracture sets to evaluate the effect of initiation direction on downstream efficiency. Second, the influence of the timing sequence of blast holes was explored within the theories of stress waves interaction and their consequent effect on fragmentation. Theoretical and numerical solutions were accompanied by six field trials in full-scale to evaluate the influence of short delay times on fragmentation and efficiency. Third, an empirical study was conducted to correlate fragmentation to the efficiency of loading and crushing; this was done to define a target fragmentation for the studied case. Finally, the techniques to assess fragmentation were discussed both quantitatively and qualitatively. The findings indicated that rockmass fractures have a significant influence on the quality of blasts and efficiency of downstream tasks. In the case study mine, adjustments to orientation of drill pattern and initiation direction of blasts suggested that careful experimentation in this regard can yield a favourable initiation direction with respect to existing discontinuities. Finer fragmentation and higher loading efficiencies can be achieved by adapting the blast designs to the existing fractures, which can lead to significant savings in the long run. On the contrary, the influence of stress waves interaction on blast results turned out to be marginal. Neither the theoretical and numerical solutions nor the field trials showed any significant improvements in blast results from short delays. In fact, it was found rather implausible to expect any noticeable improvements by using short delays. The empirical method to evaluate target fragmentation proved useful as well. It was shown that by incorporating different data from various sources in a mine, one can follow the ore from muckpile to loaders and then to crushers. Having a qualitative understanding of the fragmentation, and by developing tools to measure efficiency, one can estimate what fragmentation is most favourable for an efficient operation. Finally, two image-based methods to assess fragmentation were discussed in terms of repeatability and statistical significance. It was found that the scatter in both methods is rather large, introducing a certain ambiguity in representativeness of their results. Admittedly, it was found that in matters of long-term efficiency, the number, size and representativeness of assessed samples are of more importance compared to the accuracy of individual measurements.

Banverket har behov att det genomförs analyser till orsaker till funktionstörningar och förseningstid vid infrastrukturen. Spårväxlar är en av de anläggningar som har många funktionstörningar. Syftet med studien har varit att ta fram ett arbetssätt för att värdera enskilda spårväxlars funktionssäkerhet. Det långsiktiga målet är att minska antalet störningar på Banverkets spårväxlar och de förseningar det orsakar. En matematisk modell har använts för att presentera den information som finns samlad i Banverkets datasystem om spårväxlar. Modellen baseras på teorin om den inhomogena poissonprocessen och visas grafiskt i ett kalkylblad. Kända faktorer kan anges för varje spårväxel och det gör det möjligt att testa hur stort inflytande enskilda faktorer har. En litteraturstudie har genomförts för att ta fram förslag på faktorer. De föreslagna faktorerna kan indelas i: Startvillkor Tågtrafik Ålder Klimat Med hjälp av faktorerna bestäms om en spårväxel kan anses vara normal. Förväntas den ha fler besiktningsanmärkningar eller funktionstörningar än normalt placeras den i en "riskgrupp". Med uppgifter om vilken grupp spårväxeln tillhör, typ av spårväxel, årligt tonnage och ålder kan antalet besiktningsanmärkningar och funktionstörningar förutsägas av modellen. Spårväxlar som, efter att uppdelningen med faktorerna är gjord, upptäcks ligga utanför prediktionsintervallet för modellen kan enkelt identifieras. Metoden har tillämpats i några delstudier och använts för att förklara antalet besiktningsanmärkningar och funktionstörningar för enskilda spårväxlar eller grupper av spårväxlar på bandels nivå. Någon heltäckande förklaring till alla spårväxlars antal besiktningsanmärkningar och funktionstörningar har inte rymts inom detta projekt och det finns behov av att komplettera den information som varit tillgänglig med bland annat: Användandet av avvikande tågspår Tågens vikt, antal axlar och hastighet Banförvaltarens underhållsstrategi Arbetsättet har visat sig vara tillämpbart och i framtiden kommer metoden att utvecklas så att den kan användas för att genomföra bedömningar av livscykelkostnaden för spårväxlar. / <p>Godkänd; 2005; 20061213 (haneit)</p>

The information society, having a growing information domain/amount, requires a reliable information infrastructure with ability to distribute the right information from the right information producer to the right information consumer, at the right time and with the right quality on demand (information-on-demand). Another growing demand, parallel with the information distribution infrastructure, is information visualization. Information visualization is one of the important tools that help consumers to interpret and understand the distributed data, and facilitate the decision-making process. Maps have always been a popular method for visualizing spatial objects, objects that contain spatial references such as address co-ordinates and building ID. The rapidly growing need for geographical information systems (also called GI systems/applications) and components has an impact on the processes of development and maintenance of geographical information systems and components. The main purpose of this research is to study design patterns and suggest methods, models, rules of thumb and so on to improve the process of development and maintaining geographical information systems and reduce the total life cycle cost. The main objective is divided into following sub objectives, namely, a) to describe different patterns, solutions, models, suggestions and recommendations that can improve the process of developing GI-applications in order to reduce the cost of producing, developing and maintaining applications with a high level of quality and serviceability, b) to examine if and how the idea of design pattern is applicable to the architecture of software with spatial components (commonly called GI systems), c) to identify the factors that impact the costs of GI software development and maintenance processes and if possible recommend a model for reducing the cost and improving the quality of the solutions, d) to find and suggest solutions, models, rules of thumb, suggestions and recommendations that can improve the process of developing GI-applications. During the study, it has been noticed that recurrent GI-problems are solved but those solutions are hardly communicated among developers. On the basis of software developed in many of the research projects and also students' works we have observed that the architecture of GI software is in most cases similar to any other software. This similarity makes it possible to apply general software development patterns to GI applications. Further more it is noticed that recurring problems are not dependent on who the developer is or to what category she or he belongs, but on the problem situation and the context of the application. This means that the developer faces almost the same kinds of problems in a given situation. It has also been noticed that the size of projects and demands from customers, management, development organisations and culture/experiences, maintenance organisations and so on have an effect on how much the developer group need to use patterns and semi-manufactured components during the software development process. The study has shown that generic IT patterns can be used for designing GI-applications, but there is still a need for technology- and product-specific patterns for GI- components / <p>Godkänd; 2005; 20061213 (haneit)</p>

Banverket (‘the National Swedish Railway Administration') is responsible for management of the infrastructure in Sweden. The main objective of Banverket, stated by the Swedish government, is to assure a cost-effective and long-term provision of transportation for citizens and the business sector. In order to stay competitive with other forms of transportation, the railway needs to be cost-effective and provide reliable service. The reliable service is to a great extent reflected in terms of train punctuality. Railway components in general have a fairly long life, which means that the cost effectiveness of the transportation system is highly dependent on the effectiveness (doing the right things) and the efficiency (doing the things right) of its operation and maintenance process. The purpose of maintenance is to ensure business objectives through the assurance of required technical functions. Maintenance in the railway ensures the function of the systems that are es-sential for the operation of the transportation system. In other words, maintenance is a vital tool for achieving punctuality, which next to safety is Banverket's most important goal area. Developments in sensor technology and in the information and communication technology sector have provided new opportunities to use technology to assess infrastructural and rolling stock conditions. Decision support derived from condition monitoring systems can provide opportunities for improved maintenance management. In other words, condition monitoring can provide conditions for improved maintenance effectiveness and efficiency and hence punctuality. The thesis explores three areas. The first area is the exploration of current train delay statistics, performed in order to assess how the statistics can represent the influence of different factors on punctuality. The second is an exploration of the link between punctuality and maintenance and more specifically condition monitoring. The third area explores current condition monitoring applications at Banverket to form a knowledge foundation for further condition monitoring implementations intended to improve the reliability and hence the punctuality of the transportation system. In the perspective of the studies are important factors for successful applications of condition monitoring technology proposed. These are factors such as knowledge of problem characteristics, information accuracy, measurement limitations and ability to combine condition based maintenance objectives with business objectives etc. Furthermore, are recommendations for future condition monitoring implementations made. These are recommendations for enhancing the condition-based maintenance, which in turn is dependent on applications of condition monitoring. The final discussions are based upon overall experience from working with the material. The discussion links to the initial research problem, whose intension is to widen the horizon of possible condition monitoring applications. / <p>Godkänd; 2005; 20061213 (haneit)</p>

Several dam failure accidents have occurred during the last years and mine tailings dam failures are occurring at relatively high rates. Studies of past earth dam failures show embankment dam problems and failures are often related to internal erosion in one way or another. Geophysical methods have the potential of detecting internal erosion processes and anomalous seepage at an early stage of their development. The methods have been tested to monitor and investigate earth dams; however the methods have not been used very much in mine tailings dam. The present study has been conducted to test the applicability of geophysical methods, mainly electrical resistivity and self-potential (SP), for detecting anomalous seepage through mine tailing dams and monitoring the physical condition of the dam. Field measurements of resistivity and self-potential have been performed in the Kiruna, Aitik and Kristineberg tailings dams to look for streaming potentials, inhomogeneities and time variations of electrical properties and self-potentials. SP and resistivity measurements have also been carried out with fixed electrodes in the Kiruna and Kristineberg dam at a roughly monthly interval during one year starting in November 2003 and ending in October 2004. Laboratory measurements of resistivity have been carried out on different soil samples from the tailings dams to look for eventual changes in electrical properties with change in grain size and water content. The electric resistivity survey in the Kristineberg provides a good image of the subsurface resistivity distribution associated with filling materials and water table in the dam. The results of the electrical resistivity survey from 2004 on the Kristineberg tailings dam are fairly similar to those obtained from in 2003. The SP distribution in the dam also reveals that there are no significant changes in SP values from 2003 to 2004. The resistivity from the fixed electrodes indicates a seasonal variation in the apparent resistivity representing the freezing and thawing effect within in the dam. The SP measurements from the fixed electrode at the Kristineberg dam, shows fairly stable values during summer and more unstable during the winter probably due to change in contact resistance. The result from the 2002 SP measurements in the Kiruna dam reveals a general pattern of positive SP values at the downstream side, which is in agreement with the expected result of streaming potentials developed over the dam core. The dam was raised during the summer 2003 and new SP measurements were repeated thereafter during the autumns of 2003 and 2004 in the same areas as for the 2002 measurements. The results from 2003 measurements deviate from 2002 measurements; with in general, more negative potentials along the downstream slope. The potential distribution obtained from the 2004 measurements is compatible with the results obtained before the raising of the dam. The SP data from the fixed electrode shows unsteady physical conditions within the dam after increasing the height of the dam. The apparent resistivity from fixed electrode survey is much influenced by the variations of the pool level of the tailings pond. Some positive SP anomalies on the downstream slope of the IJ-dam at Aitik have been identified that could be related to the seepage through the dam. A distinct positive anomaly at the coordinate 7451330 north that continues to the toe of the downstream slope of the dam is generated from a known seepage of the water. The laboratory measurements on soil samples from the dams reveal a decrease in resistivity as finer particles are added to the samples that contained coarser fractions. Internal erosion may thus be reflected by increase in resistivity. This work has demonstrated the potential of using resistivity and self-potential methods for monitoring the physical condition, and the time changes in the condition of mine tailings dams. / <p>Godkänd; 2006; 20070108 (mlk)</p>

No description available.