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  • 1.
    Abdou Mahmoud, Amir
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Dahlqvist, Ted
    Halmstad University, School of Business and Engineering (SET).
    Ånghuvud för steamer2010Independent thesis Advanced level (degree of Master (Two Years)), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    The following report is for CAD-technicians 2nd year.

     

    The task that the report is built on is done in collaboration with Hafa AB. The task is to develop a new steam nozzle for steamers, a sort of combination of steam sauna and a shower. The reasoning behind the development is to make the steam nozzle match with Hafa’s current design and to gain as little wasted water as possible.

     

    There came forth a mutual idea to integrate the steam nozzle into the shower column, during a meeting with Hafa, which we developed further and became the first prototype.

     

    The prototype showed to be a success, even though protection for the steam had to be made since it flowed into the steamer at a rate which was not acceptable, mainly because little water was wasted and because the prototype was just a third of the original steam nozzle’s size.

     

    The method that we used was the same that was used by us during earlier courses in the CAD-technicians programme.

  • 2.
    Abid, Ali
    et al.
    Mälardalen University, Department of Innovation, Design and Product Development. Mälardalen University, School of Innovation, Design and Engineering.
    Roback, Joel
    Mälardalen University, Department of Innovation, Design and Product Development.
    Produktutveckling för Cate & Nelson Design: Framtagning av möbel2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport behandlar examensarbete utfört för industridesignföretaget Cate & Nelson Design. Företaget ligger i Eskilstuna och jobbar i huvudsakligen med möbeldesign och inredningsprodukter. Projektgruppensuppgift har varit att ta fram en ny möbel för företaget och arbetet har omfattat utveckling av hela produkten från idé till prototyp.

  • 3.
    Abrahamsson, Sten
    et al.
    Gotland University, School of the Humanities and Social Science.
    Isaksson, Raine
    Gotland University, School of the Humanities and Social Science.
    Implementing Lean: Discussing Standardization Versus Customization with Focus on National Cultural Dimensions2012In: Management and Production Engineering Review, ISSN 2082-1344, Vol. 3, no 4, 4-13 p.Article in journal (Refereed)
    Abstract [en]

    Lean or Toyota Production System (TPS) has more or less successfully been implemented in the Western world’s businesses and organizations for the past 20 years. Several authors have discussed what it is that creates a successful implementation, and several studies have been presented where strategies for implementations have been studied. Culture’s impact and possible mitigation for Western companies have been studied and described by for example Womak & Jones. Proponents of the concept of Lean argue that culture is not a constraint for implementation of Lean. Lean Management is called a philosophy but it is often used as a change strategy in the sense that it is implemented with the view of improving performance. A change strategy could be seen as a product that might have to be customized with the view of improving the effectiveness of the implementation. On the other hand abandoning a standardized approach comes with the risk of severely altering the change strategy, possibly to its detriment. Implementing Lean will have an effect on the company culture. Does it make any sense customizing the implementation to culture if the issue is changing the culture? The purpose of this paper is to highlight and discuss the balance between a customized implementation and a standardized implementation. Which are the main arguments for standardization and customization and how could these be reconciled? A literature study of Lean implementation has been carried out and compared with Lean principles and theories from change management with focus on change drivers and change barriers. Main drivers of Hofstede’s national cultural dimensions are compared with Lean principles to identify possible drivers and barriers in different cultures. The theory synthesis on drivers and barriers is subjected to a first test in a case study on Lean implementation according to a standardized approach. The implementation is made in a small Swedish factory belonging to a worldwide industrial company. Results from the literature review and the case study indicate that both customization and standardization are needed.

  • 4.
    Abrahamsson, Sten
    et al.
    Gotland University.
    Tosteby, Jonas
    University West, Department of Engineering Science, Division of Process and Product Development.
    Isaksson, Raine
    Gotland University.
    Integrated Management Systems: testing a model for integration2011In: 14th Toulon-Verona Conference: Organizational Excellence in Service. Conference Proceedings / [ed] Jacques Martin & Claudio Baccarani., Alicante: University of Alicante , 2011, 22-35 p.Conference paper (Refereed)
    Abstract [en]

    Management systems are widely used for creating order, minimising risks and for assuring performance. Management systems are in many occasions integrated since this has been found to be beneficial. In this paper a model for a fully integrated management system (IMS) based on the three axes of level, extent and scope of integration is tested for relevance. The studied system permits the integration of all relevant process dimensions. The research is only in a pilot stage, but the initial results are promising and indicate that there are advantages in using the process view as a base for identifying critical aspects to be managed. A review of the current situation for system integration is studied and the model is subjected to some tests using Sweden as a case. The background study shows that system integration still is limited, especially when comparing with a fully integrated IMS. The feedback from the organisations interviewed is positive and supports continued work with development of the model.

  • 5.
    Ahlman, Per-Arne
    Linköping University, Department of Mechanical Engineering, Machine Design.
    Smörjning Av Lager2009Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The work thesis was performed at Assalub a company which is situated in Åtvidaberg. The company works with developing, manufacturing and marketing equipment for handling of lubricants for light and heavier industry. The work thesis it is based on a inquiry Assalub got from MacGregor which is a company within cargo solution, from port to offshore system.

    For unloading grain and other material from the ship cargo it is used combined inlet feeder and screw conveyor, there the inlet feeder is drilling down through the cargo and feed the screw conveyer with material to further destination. At the bottom of the screw conveyer and the inlet feeder there is a bearing that keep the parts together. However the lubrication of the bearing must be made manually. Until now the bearing was lubricated manually through a grease nipple from the bottom of the drill once a day.

     

    The purpose of the thesis was the construction of a lubricating system namely a pump with a grease container which should be placed inside the space of the screw conveyer, so the bearing will be continually lubricated and able to work several days without any stoppage.

    After receiving drawings and operating data for the screw conveyer, the details for the construction was designed in CAD system Solid Edge. The solid mechanics calculations on the weakest point on the construction was made by hand and afterwards the drawings for respectively details was made.

    The construction was completed, but because of the time limit for this work thesis, the manufacturing, mounting and testing were not included in these weeks. The grease containers capacity is approximately seventy-two hours, although desirable should be up to seven days. According to the solid mechanics calculations, the construction should have no problem to resist the stresses it would be exposed to.

    Since this is a prototype there is probably some adjustments and improvements to do, but the estimating is that the system should work properly as it is now.

  • 6.
    Ahxner, Johan
    et al.
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    Axklo, Samuel
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    Införande av Lean Administration i utfallsprovsprocessen2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis concerns implementation of Lean Administration within administrative support-processes. The thesis examines how tools of Lean can contribute to the standardizing of documents and the handling of documents in order to eliminate waste. In addition, quality assurance and higher efficiency are obtained while it is possible to reach a higher capacity for value-adding activities. The empirical findings are based on action research conducted at a trading company where the supporting handling of documents concerning initial samples was studied closely.

    The background to this study can be traced to the increased global competition which has brought more companies to work with improvements to a larger extent. More companies have also decided to outsource parts of their operations to be able to focus on their core competencies. As an effect of this trend, different new actors have specialized in other areas than production. When there is no production to make more efficient, these companies have directed their work with improvements to other areas, such as the administration.

    The purpose with this thesis is to; based on Lean Administration, give suggestions for a new handling system of documents concerning the support processes for initial samples. The result of this work culminates into a proposal which is presented as a template created in Excel. The template has been created during the work with the thesis and it is built with support from principles and tools from Lean Administration. The Excel template is made to replace current documents in the specific administrative process and by doing that, contribute to standardization and increased efficiency to the work with initial samples. The template also creates options to treat customers’ different needs and it also increases quality through a built-in fail proofing feature.

    The template can be considered to be generalized and possible to implement at different companies working with initial samples. However, it may be required to change the graphical layout to company-specific needs.

    Towards the end of the writing process thoughts about developing the Excel template to a total quality document was raised. This document could contain all information concerning quality for a specific article. This idea gives opportunity for further work.

    Suggestions for further research within Lean Administration are given since there is still a lot to investigate within the field. The way the research was conducted, by viewing the work processes with Lean-glasses, can be generalized and applied to other areas than the processes concerning initial samples.

  • 7.
    Alamerison, Seif
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Tarek, Karzan
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Samverkanspelare i icke bärande fasadelement2009Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The tests work is about the subject "synergism of steel and concrete."

    The construction sector is in a strong competition and the different companies in the Prefab

    Market has ever tried to develop new design solutions that are efficient and environmentallyfriendly.

    The purpose of this report is to highlight different aspects of interaction and size up a columndimension and to examine its efficiency and load capacity as Eurocode 3 and Eurocode 4. A sizing chart that describes the relationship between the torque and normal force shouldalso be made of the interaction .

     

  • 8.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    En metod och en apparat för att prediktera tillståndet hos en maskin eller en komponent hos maskinen: PreVib algorithm2014Patent (Other (popular science, discussion, etc.))
    Abstract [sv]

    Ett ändamål med föreliggande uppfinning är att förbättra prediktionen av en tillstånds­övervaknings­parameter och därmed förbättra uppskattningen av den mest effektiva tidpunkten för att byta ut eller utföra underhåll på en maskin eller viktiga komponenter hos maskinen.

    Mätdata som används för predikteringen renas på ett sådant sätt att en optimal prediktering uppnås. Om någon del av maskinen är skadad borde mätningarna öka eftersom skadan i maskin­komponenten är irreversibel, d.v.s. den kan inte laga sig själv, vilket borde medföra att värdena på mätningarna inte kan minska över tiden. De utvalda värdena sparas i ett rörligt fönster anpassat att spara ett förutbestämt antal mätvärden.

    Predikteringen börjar när värdet av den uppmätta tillstånds­övervaknings­parametern har överstigit en potentiell skadenivå, d.v.s. skada har initierats, vid vilken det antas att en potentiell skada hos maskinen eller komponenten är initierad. Det förväntade värdet bestäms baserat på ett fördefinierat mönster som reflekterar ett förväntat beteende hos den övervakade parametern efter det att skada har initierats, och tiden som har förflutit mellan tidpunkten när mätningen utfördes och tidpunkten när övervakningsparametern översteg den potentiella skadenivån. Mätvärdena måste på så sätt uppfylla två olika villkor för att de ska tillåtas att sparas i det rörliga fönstret. 

    Predikteringen utförs baserat på mätvärden som sparas i det rörliga fönstret, dvs. som är renade från störningar. På så sätt förbättras predikteringen.

    På grund av det faktum att mätdata renas också under den första fasen är det möjligt att starta prediktionen baserat på mätvärdena som sparats i det rörliga fönstret så fort som värdet på övervakningsparametern har passerat den potentiella skadenivån. På så sätt baseras prediktionen på mätvärden sparade under den första fasen såväl som under den andra fasen.

    Tack vare reningen av mätvärdena minskas antalet nödvändiga mätningar för att åstadkomma en tillräckligt bra prediktering. Det är tillräckligt med tre mätvärden som har renats enligt uppfinningen för att få ett tillförlitligt resultat.

    Enligt en utföringsform av uppfinningen är det fördefinierade mönstret för tillstånds­övervaknings­parametern en kurva som börjar öka vid tidpunkten då övervaknings­parametern överstiger den potentiella skadenivån. Kurvan beskriver värdet hos övervaknings­parametern i förhållande till tiden som har förflutit sedan tidpunkten då övervakningsparametern översteg den potentiella skadenivån. Formen på mönstret och således på kurvan beror t.ex. på typen av parameter, typen av skada, t.ex. ett brott eller slitage, och typen av förslitningssprocess, maskinens last och hastighet, och typen och kvalitén hos maskinen eller komponenten. För många typer av fel är kurvan exponentiellt ökande. Kurvan bestäms t.ex. baserat på föregående värde för samma tillståndsövervakningsparameter för samma eller liknade typer av maskiner eller komponenter. Kurvan börjar vid samma tid som det har detekterats att en skada har initierats, d.v.s. vid den tidpunkten då övervakningsparametern överstiger den potentiella skadenivån, och kurvan ökar under hela den andra fasen. Det förväntade värdet av mätningen bestäms baserat på kurvan och tidpunkten för mätningen. På sätt är det lätt att bestämma det förväntade värdet på mätningen.

    Enligt en utföringsform av uppfinningen slängs det nya mätvärdet om mätvärdet avviker från det förväntade värdet med mer än ett gränsvärde, gränsvärdet kan vara förutbestämt eller beräknas dynamiskt under den andra fasen.

    Enligt en utföringsform av uppfinningen innehåller mätmetoden vidare: ett meddelande till användaren genereras för att kontrollera mätningen och tillhandahålla ett nytt mätvärde när man har upptäckt att mätvärdet avviker för mycket från det definierade mönstret, ett nytt mätvärde tas emot och det nya mätvärdet jämförs med det förväntade värdet som har bestämts i enlighet med det definierade mönstret för tillstånds­övervaknings­parametern, och en varning genereras om det nya mätvärdet också avviker för mycket från det förväntade värdet. I annat fall byts det äldsta av de sparade mätvärdena i det rörliga fönstret ut mot det nya mätvärdet. En ny mätning utförs om värdet på mätningen avviker för mycket från det förväntade värdet under den andra fasen. Alternativt tas ett nytt mätvärde automatiskt när det har detekterats att en mätning avviker för mycket från det förväntade värdet. I och med denna utföringsform kastas ett felaktigt mätvärde och ersätts med en ny förslitningsrelevant mätning. Om den nya mätningen också avviker för mycket från det förväntade värdet genereras en varning till användaren. Det kan antigen betyda att någonting är fel med mätutrustningen eller att skadan har utvecklats mycket fortare än förväntat och att en underhållsåtgärd brådskande behöver utföras.

    Enligt en utföringsform av uppfinningen innefattar metoden vidare: den predikterade nivån hos tillstånds­övervaknings­parametern jämförs med åtminstone ett gränsvärde för tillstånds­övervaknings­parametern, de föregående stegen upprepas åtminstone tills den predikterade nivån hos tillstånds­övervaknings­parametern överstiger gränsnivån och ett meddelande genereras avseende en underhållsåtgärd när den predikterade nivån hos tillstånds­övervaknings­parametern överstiger gränsnivån. Gränsnivån är t.ex. en varningsnivå som ligger nedanför utbytesnivån för komponenten eller maskinen. Det är också möjligt att ha flera gränsnivåer mellan den potentiella skadenivån och en utbytesnivå. Denna utföringsform gör det möjligt att föreslå en underhållsåtgärd med tillräcklig ledtid vid en kostnadseffektiv tidpunkt.

    Enligt en utföringsform av uppfinnen är maskinen en roterande maskin och mätvärdena någon av vibrationsmätningar, temperaturmätningar, ljudmätningar och chockpulsmätningar.

    Enligt en annan aspekt av uppfinningen uppnås detta ändamål av en datorprogramprodukt direkt nedladdningsbar i det interna minnet hos en dator, eller genom en fjärrstyrd dator, web-service, eller molntjänst innefattande mjukvara för att utföra stegen hos metoden när nämnda program körs på datorn.

    Enligt en annan aspekt av uppfinningen uppnås detta ändamål av ett dataläsbart medium som har ett program inspelat, där programmet får datorn att utföra stegen i metoden när programmet körs på datorn.

    Enligt en annan aspekt av uppfinningen uppnås detta ändamål av en apparat.

  • 9.
    Al-Najjar, Basim
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Determination of potential failure initiation time using cumulative sum chart2016In: IFAC-PapersOnLine / [ed] Christos Emmanouilidis, Benoît Iung, Marco Macchi and François Pérès, Elsevier, 2016, Vol. 49:28, 43-48 p.Conference paper (Refereed)
    Abstract [en]

    Hard competition forces companies to reduce uncertainty in production planning through, e.g. reducing the probability of failures. In this paper, more accurate data analysis through reducing randomness in vibration measurements is introduced. Quality control tool Cumulative Sum (Cusum) Chart is adapted for monitoring variation in vibration level to determine the time of potential failure initiation. The result confirms the possibility of reducing false alarms arise due to randomness in vibration signals. The major conclusion; applying Cusum chart it is possible to determine the time of initiation of a potential failure for follow up its progression and accurate planning of maintenance.

  • 10.
    Al-Najjar, Basim
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Algabroun, Hatem
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    A Model for Increasing Effectiveness and Profitability of Maintenance Performance: A Case Study2016In: Proceedings of 2016 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering (QR2MSE 2016) 2016 World Congress on Engineering Asset Management (WCEAM2016), Institute of Reliability Engineering , 2016, 1-7 p., QR2MSE2016 & WCEAM2016-0003-0038Conference paper (Refereed)
    Abstract [en]

    In today’s market, companies strive to achieve the competitive advantages. Failing in achieving these goals could threaten the companies’ existence. Failures in the operative level impact negatively on achieving these goals. In order to record these failures for better actions planning, special systems are often used for counting the number of failures, registering the duration of machines downtime and uptime for assessing the total downtime and classifying problems/failures in categories that are decided in advance. These categories can be Electrical, Electronic, Hydraulic, Mechanical, Pneumatics, Human error, and Miscellaneous. In this study, we develop a model to break down the contents of a company/machine failure databases, prioritize failures, assess economic losses due to failure impact on the competitive advantages and suggest a method of how maintenance actions should be rank-ordered cost-effectively. The model is tested using real data. The major results showed that losses aremainly due to two categories i.e. “Bad quality“ and “Less profit margin”, where failures of “Gear”, “Bearing” and “Raw materials quality” cause most of the losses. It is concluded that this model enables the user to quickly identify and prioritize maintenance and improvement efforts cost-effectively.

  • 11.
    Al-Sahli, Firas
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Ibrahimson, Maria
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Delaktighetens förutsättningar och begränsningar i förbättringsarbetet2016Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Participation is an important aspect when it comes to continuous improvements. Participation increases quality and creates support among employees and is a tool for achieving successful quality work. Companies need prerequisites for creating participation, and in successful companies this success is characterized by the creation of participation and motivation among employees. The aim of the study was to describe how production supervisors create opportunities for participation in improvement processes. The method used was a qualitative inductive approach from a life-world perspective. In-depth interviews were conducted with eight production supervisors and qualitative content analysis was used to examine texts to find sentence entetities and categories. Fishbone diagrams were created as a complement to the interviews. The results and the analysis indicated two categories, prerequisites and limitations to create participation in improvement work. This showed that there are difficulties when it comes to interpreting the term participation and even more difficult to specify the tools inuse. In the future it is of great importance to ensure that the research around the creation of participation is in focus.

  • 12.
    Andersson, Andreas
    et al.
    Karlstad University, Faculty of Technology and Science.
    Andersson, Anders
    Karlstad University, Faculty of Technology and Science.
    Kostnadseffektivisering av bärcylinder2007Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    The report intends a thesis work within the machine engineer program at Karlstad University, the employee is Metso Paper Karlstad AB

    Metso Paper produces tissue machines for the paper industry and also performs service and development of these products. Tissue is soft paper which includes hygiene paper and table napkins. Focus in the task is to reduce the cost of the reel drum, which is a detailed component in a tissue machine. The reel drum is a drum which is assembled in the end on the paper machine, in the area where the paper is rolled up on spools. The analyzed items have the dimensions; diameter 900mm with the length 2825 mm and diameter1100 mm with the length 5550mm.

    Initially, the reel drum’s main functions were analyzed, which can be summarized:

    • That with vacuum transport the point (narrow paper chute) from the point swindle groove to the surface between the reel drum and the reel spool

    • To support paper during winding on the reel spool

    • To create a pressure against the reel spool so that a driven torque arises. The torque is required because the reel spool has no own power supply.

    The task was divided in two parts for a simpler procedure,” new structure” and ”improvement and efficiency improvement of existing structure”

    New structure treats calculations concerning the thickness of the shell and choices of alternative materials. Improvement and efficiency concerns how the current structure can be simplified and the production process improved. The result demonstrates that today's structure is unnecessary thick, the shell thickness l can be reduced with maintained function properties. To produce the shell in steel instead of cast iron gives lower purchase cost of materials for reel drums in diameter 900mm, buying to shells at the time almost reduces the material cost with 50%

    In order to make the existing structure and the production process more effective must certain parts of the casting be carried out with higher precision, criteria such as: thickness, roundness and presence of rest products should be taken into consideration. Higher casting precision makes the following machine work easier.

    Finally there exists a big potential to reduce the cost of the reel drum. Important criteria’s that is to be considered are: dimensions, materials and more effective processing.

  • 13.
    Andersson, Andreas
    et al.
    KTH, Superseded Departments, Mechanics.
    Malm, Richard
    KTH, Superseded Departments, Mechanics.
    Measurement evaluation and FEM simulation of bridge dynamics2004Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this thesis is to analyse the effects of train induced vibrations in a steel Langer beam bridge. A case study of a bridge over the river Ljungan in Ånge has been made by analysing measurements and comparing the results with a finite element model in ABAQUS. The critical details of the bridge are the hangers that are connected to the arches and the main beams. A stabilising system has been made in order to reduce the vibrations which would lead to increased life length of the bridge.

    Initially, the background to this thesis and a description of the studied bridge are presented. An introduction of the theories that has been applied is given and a description of the modelling procedure in ABAQUS is presented.

    The performed measurements investigated the induced strain and accelerations in the hangers. The natural frequency, the corresponding damping coefficients and the displacement these vibrations leads to has been evaluated. The vibration-induced stresses, which could lead to fatigue, have been evaluated. The measurement was made after the existing stabilising system has been dismantled and this results in that the risk of fatigue is excessive. The results were separated into two parts: train passage and free vibrations. This shows that the free vibrations contribute more and longer life expectancy could be achieved by introducing dampers, to reduce the amplitude of the amplitude of free vibrations.

    The finite element modelling is divided into four categories: general static analysis, eigenvalue analysis, dynamic analysis and detailed analysis of the turn buckle in the hangers. The deflection of the bridge and the initial stresses due to gravity load were evaluated in the static analysis. The eigenfrequencies were extracted in an eigenvalue analysis, both concerning eigenfrequencies in the hangers as well as global modes of the bridge. The main part of the finite element modelling involves the dynamic simulation of the train passing the bridge. The model shows that the longer hangers vibrate excessively during the train passage because of resonance. An analysis of a model with a stabilising system shows that the vibrations are damped in the direction along the bridge but are instead increased in the perpendicular direction. The results from the model agree with the measured data when dealing with stresses. When comparing the results concerning the displacement of the hangers, accurate filtering must be applied to obtain similar results.

  • 14.
    Andersson, Ann-Christine
    et al.
    Linköping University, Department of Management and Engineering, Quality Technology and Management. Linköping University, The Institute of Technology.
    Olheden, Anna
    Landstinget i Kalmar län.
    Patient participation in quality improvement: managers’ opinions of patients as resources2012In: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 21, no 23-24, 3590-3593 p.Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate managers’ opinions of how to take advantage of patients as resources in quality improvement work in the Swedish healthcare sector.

  • 15.
    Andersson, Maria
    et al.
    Linköping University, Department of Mechanical Engineering.
    Kristofferson, Hanna
    Linköping University, Department of Mechanical Engineering.
    Structural Optimization of Product Families: With Application to Vehicle Body Structures2006Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    Some products share one or two modules and while developing these products, structural optimization with stiffness as the objective function can be a useful tool. There might be no or very little CAD-data available in the pre-development phase and it is not certain that existing designs can be, or is desirable to use as a reference. The main objective of this thesis is to establish an accurate and fast-to-use methodology which can be utilized while developing new cars.

    In this thesis, the Volvo products S40, V50 and C70 serve as a basis for this case study. All the models are beam structures and the masses of components are added as point and line masses. Several optimization analyses are performed on one or three products exposed to seven load cases. Additional analyses with shell elements, more simplified models and changed load case balance achieved by normalization of the different load case compliances are also studied to investigate how these factors influence the results.

    Analyses show that front crash to a great extent dominates the results while normalization increases the influence of the remaining load cases. Since front crash is dominating and the front area is shared in all products, the performance is remarkably similar when three products are optimized compared to separate analyses of one product. Analysis of models without added point or line masses gives a result which greatly differs from previous results and therefore shows that added masses are required. The methodology is applicable to develop products and detect new load paths through the car.

  • 16.
    Andersson, Mattias
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Kylskåpsinredning: Praktiska funktioner2008Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
  • 17.
    Andersson, Molly
    et al.
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    Andersén, Lovisa
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    SVÅRIGHETER VID CERTIFIERING AV KVALITETSLEDNINGSSYSTEMET ISO 9001:2015 FÖR SMÅ FÖRETAG2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Studien syftar till att upptäcka svårigheter vid implementering av kvalitetsledningssystemet ISO 9001:2015 på små företag. För att uppnå studiens syfte samlades teorier om kvalitetsledningssystemet ISO 9001 och dess implementerings- och certifieringsprocess in. En fallstudie genomfördes på två analysenheter för att sedan jämföras mot det teoretiska ramverket och erhålla ett resultat. De mest bidragande faktorerna till icke-certifiering av ISO 9001 hos små företag visade sig vara tidsbrist, resursbrist samt kompetensbrist.

  • 18.
    Andersson, Ola
    Kristianstad University, School of Health and Society.
    Gage R&R studie på mätutrustning för förpackningsavstånd2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of the thesis is to analyse and understand resolution, repeatability and reproducibility of the measurement system for package distance. The measurement system for package distance is already in use, no Gage R&R has been performed on the system and before spreading use of the system the quality of the system has to be understood and approved

  • 19.
    Andersson, Viktor
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Olsén, Martin
    Halmstad University, School of Business and Engineering (SET).
    Kilhus i plast: Omläggning av stålprodukt till produkt i plast2010Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Our bachelor degree thesis was carried out in collaboration with Ivar Petterssons Järnmanufaktur AB in Smålandsstenar. We were asked to replace their wedge housing, used to fasten the wires to the power lines, with a similar structure in a plastic material. The idea for this project started with Ivar Petterssons Järnmanufaktur AB having problems with the casting quality that forced them to perform expensive tests on each of the wedge houses to ensure the quality. They are currently produced in China which is also a major drawback because it requires expensive long delivery times.

    The method we used is Fredy Olsson's Princip- and Primärkonstuktion (1995). We have consistently been in the project on so-called "broad front", which means that you create several sketches, ideas and changes in parallel, and then evaluates all. With this method we were able to largely concentrate on the current part of the project, rather than using the more time-consuming "trail and error" method, which is basically doing one idea at a time, and evaluate them one by one.

    At first we were very optimistic and thought we would be able to order form for the injection moulding process, but as the project progressed we found we were not certain that the product would hold and we were forced to present the solution as a concept that will require testing before it’s finished, and not a finished solution.The results we presented for Ivar Pettersssons Järnmanufaktur is a complete drawing on our primary solution, including the release angles. This is because when they decide to go forth with the project, it will be possible to produce a tool without having to make changes to the drawings. Temporary financial calculation shows that the savings may be realized around 1 300 000 SEK by switching to a plastic construction. However we have not been able to verify hours and therefore no cost estimates for the testing done in Sweden, so the actual amount of money saved is larger.

  • 20.
    Anundi, Elina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Kundlojalitet i mindre B2B företag2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Är nöjda kunder automatisk lojala kunder? Det krävs mer än bara en positiv upplevelse av servicekvalitet för att nå hög lojalitet bland sina kunder. Trots att kunderna upplever servicen lika, kan deras bedömning av tillfredsställelse variera p.g.a. olika förväntningar och prioriteringar. Upplevd servicekvalitet och tillfredsställelse är de första faktorer som påverkar lojalitet. Men det krävs också förtroende för såväl företaget som också på individnivån till företagets representanter, innan kunderna vågar binda sig till en relation med en leverantör. Allt detta påverkar relationen, som med tiden kan utvecklas och fördjupas. Det är alltså servicekvalitet, tillfredsställelse, förtroende samt beredskap att binda sig till en relation och relationskvalitet som påverkar lojalitet i olika utsträckning inom olika branscher.

    Den empiriska undersökningen som genomfördes i form av en webbenkät bland kunder hos ett mindre Business-to-Business (B2B) företag visar att segmentering baserad på lojalitet är ett effektivt sätt att skapa förståelse för hur lojala och icke-lojala kunder ser på företaget och deras servicekvalitet. Segmentering baserar på några extra frågor som mäter lojalitet. Trots låg antal svar (17 svar) är resultat enhetlig för varje segment och visar därmed vilka brister som bör åtgärdas.  

  • 21.
    Arvidsson, Totte
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Det kommunala ledarskapet i det förebyggande krisberedskapsarbetet- En kris eller en möjlighet?: Kvalitativ studie- med utgångspunkt i offensiv kvalitetsutveckling2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study, with it ́s base in Total Quality Managment, was to contribute with knowledge about the minuicipal leadership and the proactive crisismanagment. The method that has been used has been hermenetuic, inductive and qulitative method. A multiple casestudy has been made through three interviews with crisis coordinators in the municipal sector. The questions in the study have been semistructurated. The questionnaire was made with the influence of Appreciative Inquiry. The conclusion was that the municipal leadership have strengths and opportunities to development in the proactive crisimanagment. There was strengths and opportunities in all six principels in Total Quality Management. These strenghts and opportunities in the municipal leadership could contribute to a positive developmen of the crisismanagment and create a safer community. Exampels of perceived strenghts was municipal leaders that alowed participation in risk- and vulnerabillity assessments and educations. Exampels of development areas of municipal leaders was that leaders schould contribute to openness, responsiveness, participation and discussions regarding crisis management.

  • 22.
    Assarsson, Felix
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Håkansson, Fredrik
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Guide till ATEX: Framställning av ett virtuellt verktyg för arbete med ATEX hos Plåt och spiralteknik AB2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I detta arbete har vi fördjupat oss i ATEX-direktiven för att undersöka hur Plåt och spiralteknik ABs arbete på området kan förbättras. I dagsläget säljer företaget ATEX-godkänd utrustning periodvis men anser att deras kunskaper om ATEX inte är tillräckliga för att tillgodose alla kunders behov. Målet med detta arbete var att ta fram en manual för de regler kring explosionsförebyggande föreskrifter som gäller företagets produkter. Detta arbete har resulterat i en manual i form av en lathund för arbete med ATEX anpassad för PSTs verksamhet.

  • 23.
    Attervall, Sebastian
    et al.
    Linköping University, Department of Management and Engineering.
    Gustafsson, Nichlas
    Linköping University, Department of Management and Engineering.
    Styrning och nödbroms av ModuLith2008Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    The purpose of this project is to get a fully functional, automatic steering system and a variable breaking system with an emergency breaking function to an off road vehicle. This off road vehicle is supposed to work as an aid in military situations. A team of two, Sebastian Attervall and Nichlas Gustafsson, got an order from Jonas Nyårds and the PreeRunners Project to construct a steering system that could manoeuvre an off road vehicle without any human involvement. To make this possible the vehicle would be guided by onboard sensors, cameras and computers. The team where also assigned to construct an automatic breaking system, there also no human would be involved. The breaking system should as well contain an emergency stop function to prevent any accidents. The team has solved the problems assigned by using theories by David G. Ullman. The system that was eventually chosen was a steering system containing a 48V, 250W DC motor. A planetary gear where chosen to increase the torque from the engine. To translate the torque from the planetary gear to the steering bar a chain with chainwheel where chosen, this because the chain and chainwheel could withstand the immense forces acting on the chain. Between the planetary gear and the chainwheel a skid clutch is placed to prevent destruction on the planetary gear due to overload. The whole steering system is monitored by two rotary encoders, one placed on the engine and one placed on the steering bar. The breaking system eventually chosen where a system build on the existing drum brakes, placed in the front. To make the system independent from any human interference a system containing a linear motor, an electromagnet and a spring where chosen. The system works by letting the spring act on the wire from the existing drum breaks. The spring is always compressed so a force will always act on the wire when the system is at rest. By compressing the spring further the force acting on the wire will decrease and by compressing it enough the breaks will be released. The force compressing the spring will come from the linear motor. And to make the system failsafe in case of an emergency an electromagnet will be placed between the linear motor and the spring. When the power is cut to the electromagnet the compressed spring will be released and the drum breaks will break. The breaking system as well will be supervised by encoders and in this case linear encoders.

  • 24.
    Au-Yeung, Ginsun
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences. Uppsala universitet.
    Andersson, Mattias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences. Uppsala universitet.
    How can Lean contribute to create effective meetings?: A case study at Ericsson in Borås2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Lean is a philosophy that has been studied extensively in recent years, and it has been successfully implemented in a number of different processes and businesses. This study aims to examine how Lean can contribute to create effective meetings, which is a topic that has received limited attention in today’s research.

    Firstly, a situation analysis is done in order to identify common meeting problems at Ericsson Borås. Secondly, a comprehensive analysis is conducted concerning whether Lean is applicable on meeting processes or not. This analysis is mainly based on the five principles of Lean Thinking. Thirdly, the study investigates the potential effect of an implementation of Lean, as well as how Lean principles can be applied in order to reduce or eliminate wastes.

    The result of the analysis formed the base for the development of the action plan. Subsequently, the action plan is implemented on the meeting processes by pilot testing it on three different meetings. This analysis is mainly focusing on whether the meeting problems have been eliminated or not.

    Based on our research, we have perceived that almost every meeting is unique and all meeting problems we have identified do not occur at all meetings. Majority of the meeting problems were eliminated by applying Lean principles. Moreover, several respondents also expressed that Lean is a good way to give more structure to meetings, and therefore contributes to more effective meetings. However, we have noticed that principles of Lean cannot eliminate all meeting problems at Ericsson. This can be seen as minor criticism when organizations use Lean as the only solution to improve meeting processes.

  • 25.
    Axelsson, Daniel
    Linköping University, Department of Management and Engineering.
    Design and Development of a Spray Booth2008Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    As a part of a more extensive project of developing a new finishing line at the Bolivian door manufacturer Tecno Carpinteria San Pedro this thesis presents the development process for a special designed spray booth. The thesis covers every phase from a product idea to a final concept design.

    Working with finishing of furniture and other wooden products can effect the workers health in a negative way and damage the environment. The final result of the manufactured door is also depending on the how well the ventilation system in the working area is. Because of these reasons it is important to use safety equipment and a good ventilation system in the working area. As a part of this new finishing line San Pedro is in need of a special designed spray booth to control the spread of paint particles and other hazard substances that is a result of the finishing process.

    Together with the consultant firm CADEFOR a spray booth is designed and a proposal design is presented in this thesis. The result is a design built up with a dry filter solution together with an extractor that creates a cross draft airflow towards the rear part of the spray booth. The result of the project together with some recommendations of increasing the capacity in the finishing line are also presented.

  • 26.
    Backlund, Fredrik
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Chronéer, Diana
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Sundqvist, Erik
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Maturity assessment: towards continuous improvements for project-based organisations?:2015In: International Journal of Managing Projects in Business/Emerald, ISSN 1753-8378, E-ISSN 1753-8386, Vol. 8, no 2, 256-278 p.Article in journal (Refereed)
    Abstract [en]

    PurposeThe aim of this study is to contribute to the empirical research on project management maturity assessments, specifically based on a maturity model. Design/methodology/approachThe empirical data is based on a case study including in-depth interviews with a semi-structured approach, followed by a focus group interview. A survey was distributed within a project-based organisation and to client and stakeholder representatives, and then analysed. The organisation in the case study is a project department within a Swedish mining company. FindingsCareful considerations are needed when choosing a project management maturity model (PM3) as the model structure can influence the assessment’s focus. It is also important to include both internal and external project stakeholders in the assessment to achieve an efficiency and effectiveness perspective when analysing PM capabilities. Valid information from an assessment is crucial, therefore, clear communication from management is important in order to motivate the participants in the assessment. Research limitations/implicationsImproved understanding for implementing and applying a PM3 contributes to the increased knowledge of drivers, enablers and obstacles when assessing PM maturity, which also creates a basis for further research initiatives. Practical implicationsAn increased knowledge of drivers, enablers and obstacles should be valuable for practitioners introducing and applying a PM3.Originality/valueThis case study gives an in-depth insight into the implementation of a PM3 within a project-based organisation. Through conducting a literature review, it was found that this type of empirical research is rare

  • 27.
    Backlund, Fredrik
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Chronéer, Diana
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Sundqvist, Erik
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Project Management Maturity Models – A Critical Review: A Case Study within Swedish Engineering and Construction Organizations2014In: Procedia - Social and Behavioral Sciences, ISSN 1877-0428, E-ISSN 1877-0428, Vol. 119, 837–846- p.Article in journal (Refereed)
    Abstract [en]

    Different kinds of project management maturity models (PM3s) exist today, most of them inspired by the capability maturity model (CMM) developed in the beginning of the 90ies, originally intended to measure capability in software development projects. Research indicates that organizations with higher project management (PM) maturity levels are expected to be successful in terms of project effectiveness and efficiency, and thus have a competitive advantage in the marketplace. Though, despite several PM3s developed during a time period of over 20 years, knowledge about how PM3s are a*pplied in organizations is sparse within the PM literature. This paper explores how major engineering and construction companies view PM maturity and PM3s in order to develop and improve their PM practices. These kinds of organizations are mainly project-intensive, objective oriented,and have the capabilities to perform overall business development initiatives, i.e. suitable for applying PM3s.The contribution of PM3s to organizational improvement and development is somewhat unclear. Therefore, a literature review highlights different aspects regarding PM3s, specifically their purpose, strengths, and weaknesses. To what extent PM3s are used, interviews have been conducted with seven respondents within different project intensive organizations, in their roles as project managers or in charge of PM development. How a PM3 can beintroduced and applied is explored via an in-depth case study at the major mining company in Sweden, LKAB. However, tentative results show that the application of PM3s in Swedish engineering and construction organizations are limited, indicating that further research is needed

  • 28.
    Bagampadde, Umaru
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Investigations on moisture damage-related behaviour of bituminous materials2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This doctoral thesis presents results of literature review on classical and contemporary aspects of stripping, as well as experimental investigations on moisture damage as influenced by bituminous materials.

    Previous research in the area of moisture damage was reviewed and synthesized into a state-of-the-art. Important parameters linked to moisture sensitivity, like bituminous material characteristics, dynamic loads from heavy vehicles, environmental factors, construction practice and nature of anti-stripping additives, are presented. The state-of-the-art in current test methods is summarized and given.

    The experimental work involved investigations of the influence of bitumen and aggregate composition on water susceptibility. The influence of aggregate mineralogy and chemistry was evaluated using eleven aggregates and one bitumen, followed by studying the interactive effect of four bitumens and four aggregates. Moisture sensitivity was evaluated in accordance with (EN 12697-12:2003) for conditioning, ASTM D 4123 for resilient modulus determination, and (EN 12697-23:2003) for indirect tensile strength testing. Furthermore, thermal stability of two liquid amine anti-stripping additives mixed with two bitumens of varied acidity was investigated using potentiometric titration and Fourier Transform Infrared (FTIR) Spectroscopy. Lastly, a technique based on Fourier Transform Infrared Spectroscopy-Attenuated Total Reflectance (FTIR-ATR) was developed and used for studying transport of water across thin bitumen films, as well as stripping at bitumen/substrate interfaces. Bitumens from different sources and three substrates (silicon, germanium and zinc selenide crystals) were used. Based on the results obtained, it was concluded that aggregates containing sodium and potassium in alkali feldspars generally showed high moisture sensitivity. In contrast, presence of calcium, magnesium and iron was associated with aggregates with low moisture sensitivity. Contrary to several previous findings, one aggregate with practically 100% quartz exhibited low moisture sensitivity. No linear relationship between moisture sensitivity and the contents of SiO2 and Al2O3 in the aggregates studied was established. Results of the interactive influence of bitumen and aggregate composition showed that high acid and low penetration bitumens exhibited high dry strength for all the aggregates studied. On the other hand, for a given bitumen, the wet strengths were found to be aggregate specific.

    The results of tests on thermal stability of amine additives showed that usefulness of these additives reduces considerably, when the more alkaline additive was mixed with the high acid bitumen, followed by storing the blends under pronounced conditions of time and temperature (24 hours and 140ºC, or more, in this study). Much less interaction occurred when the less alkaline additive was blended with the low acid bitumen. Even if a correlation was found between the results of potentiometric titration and Fourier Transform Infrared spectroscopy, the latter was not considered good enough at detecting amine additives, especially at low dosages.

    The technique based on FTIR-ATR developed in this study distinguished between good and bad bitumens with regard to stripping. The effectiveness of amine-based additives in reducing stripping was also shown by the method. Three likely processes occurred during the test, namely water diffusion, film break, and displacement (stripping) of bitumen from the substrate surface. The results also indicated that the diffusion process of water into the bitumen/substrate interface does not obey Fick’s law.

  • 29.
    Bagampadde, Umaru
    et al.
    Faculty of Technology, Makerere University, Kampala.
    Isacsson, Ulf
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Characterization of chemical reactivity of liquid antistripping additives using potentiometric titration and FTIR spectroscopy2006In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 20, no 5, 2174-2180 p.Article in journal (Refereed)
    Abstract [en]

    Chemical reactivity of two liquid antistripping additives mixed with two bitumens of diverse acid numbers was evaluated. Additives present in the blends were detected by use of potentiometric titration and infrared spectroscopy. Tests were done at dosages of 0, 0.5, 1.0, and 2.0%; storage temperatures of 25, 100, 140, and 150 degrees C; and storage times of 1, 24, and 72 h. At 0.5% dosage, close to typical field values, the more basic additive mixed with bitumen of high acid number almost ceased to be detected after 24 h of storage at 140 degrees C. The less basic additive could be detected beyond these conditions, irrespective of the bitumen used. At higher dosages, reactions with the bitumens were found to be more pronounced with the more basic additive. The reactions between the additives and bitumens studied seemed to be higher in the bitumen with higher acid number, irrespective of the dosage. Statistical analysis indicated that all the parameters studied significantly affected change in amount of additives detected in the blends. A correlation was established between potentiometric titration and infrared spectroscopy in detecting amine additives. This correlation notwithstanding, infrared spectroscopy was found to not be a good tool for measuring amines in the blends, especially at low concentrations.

  • 30.
    Bagampadde, Umaru
    et al.
    Makerere University, Kampala.
    Isacsson, Ulf
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Kiggundu, Bob
    Makerere University, Kampala.
    Influence of aggregate chemical and mineralogical composition on stripping in bituminous mixtures2005In: The international journal of pavement engineering, ISSN 1029-8436, Vol. 6, no 4, 229-239 p.Article in journal (Refereed)
    Abstract [en]

    The influence of aggregate chemical and mineralogical composition on moisture sensitivity was investigated using 11 aggregates from typical tropical and temperate climates and one bitumen. Mix design and compaction were based on Swedish Road 94 hot mix base specifications and moisture damage was determined using resilient modulus and tensile strength ratios. As much as practically possible, air voids, gradation, compaction level, bitumen content and curing were controlled. Mixtures from aggregates containing sodium and potassium exhibited relatively high moisture sensitivity. The converse was apparent for aggregates with calcium, magnesium and iron. No significant correlation was observed between the strength ratios and contents of Al2O3 and SiO2. Stripping was generally high for aggregates with quartz and alkali feldspars, although one aggregate with practically 100% quartz showed low moisture sensitivity. Statistical analysis showed good correlation between resilient modulus and tensile strength ratios.

  • 31.
    Bagampadde, Umaru
    et al.
    KTH, Superseded Departments, Civil and Architectural Engineering.
    Isacsson, Ulf
    KTH, Superseded Departments, Civil and Architectural Engineering.
    Kiggundu, Bob
    KTH, Superseded Departments, Civil and Architectural Engineering.
    Classical and contemporary aspects of stripping in bituminous mixtures2004In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, Vol. 5, no 1, 7-45 p.Article in journal (Refereed)
    Abstract [en]

    Stripping or removal of bitumen from an aggregate because of water penetrating into the interface causes many pavements to fail. Stripping has been existent since the advent of paving technology. It causes functional weakening of pavements leading to costly repairs. This state-of-the-art paper deals with important concepts of stripping as, bitumen chemistry and rheology, aggregate properties (chemical and mineralogical composition, surface texture, morphology, porosity, etc), traffic, water properties, construction practices (mixing, placement and in-service drainage) and nature of antistripping additives. Adhesion of bitumen onto aggregate is explained based on theories like mechanistic tenacity, molecular orientation, chemical reaction, and thermodynamic balance of interfacial forces. Stripping is elucidated using several mechanisms namely, displacement, detachment, spontaneous emulsification, bitumen film rupture, water pore pressure, hydraulic scouring, chemical disbanding, microbial activity, osmosis; and blistering and pitting. Attendant theories to the mechanisms are explained. Moisture sensitivity test methods emerged are described and discussed. The large number of tests that have evolved shows the importance of the phenomenon of stripping. Remedial measures which include use of antistripping additives, careful selection of hot mix component materials, good construction practice, and others have been proposed for use in practice.

  • 32.
    Bagampadde, Umaru
    et al.
    Makerere University, Kampala.
    Isacsson, Ulf
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Kiggundu, Bob
    Makerere University, Kampala.
    Impact of bitumen and aggregate composition on stripping in bituminous mixtures2006In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 39, no 287, 303-315 p.Article in journal (Refereed)
    Abstract [en]

    The impact of bitumen and aggregate composition on stripping was investigated using four bitumens and four aggregates. Moisture sensitivity was assessed based on retained resilient modulus and tensile strength ratio (MRR and TSR, respectively). The results indicate that mixtures from the bitumen with a high acid number exhibited high resilient modulus and tensile strength in the dry condition for all the aggregates. In wet condition, this conclusion did also hold except for one aggregate. Regarding penetration grade, mixtures made with lower penetration grade bitumen exhibited higher resilient modulus and tensile strength, in dry and wet conditions, than those of higher penetration grade. Bitumen characteristics like acid number, penetration grade and molecular size distribution did not influence moisture sensitivity. Mixtures with aggregates containing alkali metals (sodium and potassium) exhibited relatively high moisture sensitivity, regardless of the bitumen used. In contrast, indications of moisture sensitivity were not apparent in mixtures made with aggregates containing calcium, magnesium and iron. Data analysis revealed that variability in moisture sensitivity is attributed to aggregate rather than bitumen. No significant interaction effect between bitumen and aggregate was found on moisture sensitivity. The results indicated good correlation between MRR and TSR in ranking mixtures for stripping.

  • 33.
    Barsoum, Zuheir
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. Khalifa University.
    Bhatti, Ayjwat
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Balawi, S.
    Computational Weld Mechanics - Towards a Simplified and Cost Effective Approach for Large Welded Structures2015In: Procedia Engineering, 2015, 62-69 p.Conference paper (Refereed)
    Abstract [en]

    The current paper presents the development of a finite element analysis framework for computational weld mechanics, in order to carry out cost-effective predictions of welding induced residual stresses with good accuracy. Different approaches for describing the welding heat sources were investigated. The paper also investigates the influence of thermo-mechanical material properties of frequently used steel grades (S355-S960) on welding residual stresses and angular distortion. The predicted residual stresses were validated experimentally on several different small scale specimens with X-ray diffraction techniques. Finally, the developed simulation framework is demonstrated on complex welded structures in a construction equipment vehicle.

  • 34.
    Belov, I.
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing - Surface technology.
    Alavizadeh, Z.
    Lindgren, M.
    Application of engineering optimization to evaluate heating-based humidity management in electronics enclosures2011In: Electronic Environment Konferens & Mässa 2011, Stockholm Älvsjö,5-6 April 2011, Invited speech, 2011, 161-162 p.Conference paper (Other academic)
  • 35.
    Bengtsson, Marcus
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Fundin, Anders
    Mälardalen University, School of Innovation, Design and Engineering.
    Deleryd, Mats
    Mälardalen University, School of Innovation, Design and Engineering.
    Salonen, Antti
    Mälardalen University, School of Innovation, Design and Engineering.
    Olsson, Erik
    Mälardalen University, School of Innovation, Design and Engineering.
    Funk, Peter
    Mälardalen University, School of Innovation, Design and Engineering.
    Andersson, Carina
    Mälardalen University, School of Innovation, Design and Engineering.
    Qureshi, Hassan
    Mälardalen University, School of Innovation, Design and Engineering.
    Integrating Quality and Maintenance Development: Opportunities and Implications2010In: Proceedings of the 23rd International Congress on Condition Monitoring and Diagnostic Engineering Management (COMADEM 2010): Advances in Maintenance and Condition Diagnosis Technologies towards Sustainable Society / [ed] S. Okumura, T. Kawai, P. Chen, and R. B. K. N. Rao, 2010, 821-828 p.Conference paper (Refereed)
    Abstract [en]

    Today, the drive in many organizations is to focus on reducing production costs while increasing customer satisfaction. One key to succeed with these goals is to develop and improve both quality and maintenance in production as well as quality and maintenance in early phases of the development processes. The purpose of this paper is to discuss how and motivate why research within quality and maintenance development may interact, in order to help companies meet customer demand while at the same time increase productivity. The paper is based on ideas and research perspectives of the newly formed competence group on ‘Quality- and Maintenance Development’ at the School of Innovation, Design and Engineering at the Malardalen University, Sweden. This paper elaborates on the concepts of Quality and Maintenance, its important integration, and provides some examples of ongoing research projects within the competence group.

  • 36.
    Bengtsson, Per-Johan
    Halmstad University, School of Business and Engineering (SET).
    Autotving: Utveckling av en ny typ av enhandstving2011Independent thesis Basic level (degree of Bachelor), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [sv]

    Då hantverkare jobbar ensamma behövs ofta en extra arm. Dagens enhandstvingar är inte optimala att hantera med endast en hand. I detta projekt har därför ett underlag för en ny typ av enhandstving arbetats fram. Arbetet avgränsades till princip- och primärkonstruktion.Resultatet är en tving som i mycket liknar tvingarna på marknaden idag. Skillnaden är att de båda käftarna dras ihop med hjälp av gummiband innan den slutliga förspänningen sker. För att åstadkomma detta var mekanismen i tvingen tvungen att göras om, samt att designen på tvingen var tvungen att anpassas till de nya komponenterna. Ingen prototyp har byggts, istället har en mycket detaljerad 3d-modell av tvingen arbetats fram.

  • 37.
    Berg, Kristoffer
    et al.
    Linköping University, Department of Management and Engineering.
    Lindholm, Jonas
    Linköping University, Department of Management and Engineering.
    Vibrationsisolering av gruvmaskinshytt2007Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    The aim of this thesis, commissioned by Atlas Copco Rock Drills AB, is to investigate the vibration problems concerning the Scaletec MC and give proposals on new concept solutions that improve the handling of the vibration problems. The solutions are limited to the cabin and the cabins connection to the frame. The conclusion tells us that the most important issue is the long reaching boom with the hydraulic hammer attached to it. This assembly creates movements in the cabin during scaling and transportation. The non-damped transportation chair, the rough roads and the stiff axles are also factors that create problems with whole body vibrations.

    The concept phase focused on finding a robust and compact design that, with the correct degree of freedoms, reduces the influence of the vibrations. The result consists of two solutions, both controlling and managing the existing vibrations. The first solution focuses on the flaws that the existing system possesses and the other is designed to handle greater vibration levels.

  • 38.
    Bergdahl, Nina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Co-Creative Learning - using IT to Visualise Progression (CIP): En studie av former för systematiskt kvalitetsarbete på klassrumsnivå2016Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the study is partly to understand how systematic quality management can be implemented at the classroom level and partly what it means to apply it from a student perspective, and to compare student progression with that of a control group. As a result of this, this study contributes with a method on how quality management can be implemented at the classroom level. This working method is named Co-Creative Learning - using IT to Visualise Progression.

    This is an action research study that encompassed questionnaires, focus groups and a time series. Three assignments from 65 students were assessed in the study, out of which two were compared to those from the control group.

    To enhance reliability and validity the selected control group were from the same catchment area, had qualified teacher with corresponding number of working years who also worked with formative assessment and visualising criteria. Two assignments were identical for both groups, and thus, the two groups' results could be compared.

    To minimise the effects of the presence of a teacher during evaluation, the students were not brought together to form focus groups, until after the grades were communicated. They then reflected on continuous improvement efforts, quality, inclusion, understanding objectives, perceived progression and the use of IT.

    Before the concluding discussion the collected data sets were analysed separately. The results showed the difference in both student experience and progression. The main differences lay in the student experience: where change primarily affected the students’ involvement; the extent to which the students were satisfied students with their own development.

    In the time series, the differences were not as high as in the student experience. The studied group started at a slightly lower grade, and completed at a slightly higher grade, than the control group. It was mainly the boys who accounted for the progression. One reason for could be that the girls

    already held high average grades (leaving little room for progression). Compared to the control group, the differences with the boys in the studied group remains.

    The conclusions drawn are thus that the method enhances progression, but that the main benefits are harvested from the enhanced educational experience of the students.

  • 39.
    Bergdahl, Stefan
    Linköping University, Department of Mechanical Engineering.
    Undersökning av svetsförband med avseende på svetsgeometri, diskontinuiteter och blästring med stålkulor2006Independent thesis Basic level (professional degree), 20 points / 30 hpStudent thesis
    Abstract [en]

    Breakdowns of welded structures are usually a consequence of fatigue loading. Fatigue fractures are commonly initiated in the region close to the weld toe but can also initiate from the weld root and from discontinuities inside the weld. The purpose of this investigation was to examine the weld quality of welded joints produced at Volvo Wheel Loaders factory in Arvika. The goal of the investigation is to give a clearer insight regarding factors influencing the fatigue strength of the welded joints and thereby give a better foundation for fatigue strength calculations.

    The investigation is including examination of the weld geometry, weld discontinuities and the effects of shot peening. Mainly three different methods for collecting test data have been used: Plastic replicas cast on the weld profile, weld specimens from a rear frame belonging to a wheel loader of model L110E/120E and Almen testing of the shot peening.

    The results showed that it is not possible to control even transition between the weld material and the base material without after treatment. The most frequent reason why the welded joints did not fulfill the demands in the Volvo Corporate Standard was leg deviation outside the acceptable limit. The most frequent weld defect was lack of fusion inside the weld. The occurrence of this defect was overrepresented in butt welds. The results also showed that the fatigue enhancing effects of shot peening are with today’s process just being used to a minor degree.

  • 40.
    Bergkvist, Sandra
    et al.
    Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Läbom, Malin
    Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Motordrivet höj- och sänkbart TV-stativ: Motor-driven rise- and sinkable TV-stand2008Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [en]

    This master's thesis has been performed in cooperation with the company ROL Ergo which design and manufacture motor-driven rise- and sinkable desks. The company wants to expand their assortment by marketing motor-driven rise- and sinkable TVstands towards the public service. The stand shall be designed with the same technical solutions and principles as the company already applies. The mission was given out as a master thesis to Jönköping University. The authors has through a given requirement specification and own field studies on the market made the foundation for the development of the TV-stand. Through different well known working methods the work has been charted, planed in detail and supporting in decisions of greater and smaller concept selections.

    The requirements and desiderates from potential costumers has accurately been worked thru to be fulfilled one at a time and they have also been supporting in decisions of technical and designable shaping. The constructions is build up with support from predetermined parts that was given from ROL Ergo and thru investigations in the ergonomic area, practical laboratory work, computing and discussions with the mentor on the company. A rough construction was developed as a base for the whole product and from that upcoming problems could be discussed and solved to supply the main part of the requirements and desires. After that piece by piece was designed in a detail construction phase to work together in the end as an overall solution. The result becomes a mobile motor-driven TV-stand that can take TVs up to 42". The stand is ergonomically suitable for both a sitting and standing audience. The TV-stand is designed to fit well in public services and is therefore styled discreet and sobered with few visible details.

  • 41.
    Bergquist, Bjarne
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Traceability in iron ore processing and transports2012In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 30, 44–51- p.Article in journal (Refereed)
    Abstract [en]

    The ability to track and trace products in a production process and in the transportation chain from supplier to customers is important for quality control and process improvements. However, good traceability is often difficult achieve for continuous process products as well as for batch produced products where batches intermix. In this paper, guidelines for improving traceability and setting up a traceability system in the iron ore production process are presented based on two case studies. One case is using process data in a simulation approach for a pellets plant and the other is using RFID methodology to trace pellets in the distribution chain. Results show that simulations can aid short-term traceability, whereas long term traceability is possible through marking pellets with RFID transponders, where the applications are suitable.

  • 42.
    Bergquist, Bjarne
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Some ideas why factorial designs are not used in full-scale experiments in continuous processes2015In: Total quality management and business excellence (Online), ISSN 1478-3363, E-ISSN 1478-3371, Vol. 26, no 11-12, 1242-1254 p.Article in journal (Refereed)
    Abstract [en]

    This paper presents ideas and observations about the infrequent use of factorial experimental designs; although the ideas presented are inspired by a case study, the paper is also conceptual in nature. The ideas build on the experimental practices at a large Swedish process industry manufacturer, where these practices were discussed with engineers using in-depth interviews. Factorial design is not used because, for example, statistical rigor is seldom required and because design of experiments methods are seen as too restrictive to accommodate and adjust to events occurring during long experimental campaigns. The interview results indicate that, while the scepticism of many respondents may be justified, lack of training, interest, and learning time are major obstacles to applying improved methodologies. Some ideas for overcoming these obstacles are suggested.

  • 43.
    Bergquist, Bjarne
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Project: DISIRE2015Other (Other (popular science, discussion, etc.))
  • 44.
    Bergquist, Bjarne
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Analysis of an unreplicated 2^2 factorial experiment performed in a continuous process2015In: Total quality management and business excellence (Online), ISSN 1478-3363, E-ISSN 1478-3371, Vol. 26, no 9-10, 1083-1094 p.Article in journal (Refereed)
    Abstract [en]

    This paper presents a tentative analysis method for unreplicated factorial designs where regular statistical experimental analysis cannot be used. The methodology is demonstrated through the analysis of an unreplicated two-level, two-factor factorial experiment performed in a continuous production process where the process was not in statistical control and where changes in the experimental design made conventional experimental analysis impossible. The first step of the analyses included screening of the sampled data. Principal component analysis and factor analysis were then used to create an overview of how the various responses and experimental factors were related. Carbon monoxide efficiency was selected as the most important parameter to be analysed further. Elastic net regression was used as a screening tool to remove non-significant factors, interaction, and covariates. Finally, the carbon monoxide efficiency variation was modelled using an intervention analysis. Two experimental factors were found to actively influence the response. The experiment that from other perspectives can be considered to be unanalysable, did thus reveal causal effects. The results imply that for processes where the process dynamics may be monitored, observations of the process dynamics may reduce the needs for repeated experimental runs, thus reducing the experimental costs.

  • 45.
    Bergquist, Bjarne
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Garvare, Rickard
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Evaluating Quality of Higher Education by Assessing its Output: The Swedish Example2013In: 16th QMOD-ICQSS Proceedings: Quality Management and Organizational Development Conference / [ed] Su Mi Dahlgaard Park, Moderna Organizacija , 2013, 216-222 p.Conference paper (Refereed)
  • 46.
    Bergquist, Bjarne
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Garvare, Rickard
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Eriksson, Henrik
    Chalmers tekniska högskola, Teknikens ekonomi och organisation.
    Hallencreutz, Jacob
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Langstrand, Jostein
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Avdelningen för Kvalitetsteknik.
    Vanhatalo, Erik
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Alive and kicking–but will Quality Management be around tomorrow?: A Swedish academia perspective2012Conference paper (Refereed)
    Abstract [en]

    Purpose: There is a lack of a recognized conception of quality management (QM) comprises of, as well as a clear roadmap of where QM is heading. The purpose of this article is to investigate how QM is perceived today by scholars at three Swedish universities, but also how and into what QM is expected to develop into in twenty years.Methodology: Data have been collected through three structured workshops using affinity diagrams with scholars teaching and performing research in the QM field affiliated with three different Swedish universities.Findings: The results indicate that current QM is perceived similarly among the universities today, although the taxonomy differs slightly. QM is described as a fairly wide discipline consisting of a set of core of principles that in turn guide which methods and tools that currently by many are perceived as the core of the discipline. The outlook for the future differs more where three possible development directions for QM are seen: [1] searching for a “discipline X” where QM can contribute while keeping its toolbox, [2] focus on a core based on the traditional quality technology toolbox with methods and tools, and [3] a risk that QM, as it is today, may seize to exist and be diffused into other disciplines. Originality/value: This article contributes with a viewpoint on QM today and its future development from the academicians’ perspective.

  • 47.
    Bergquist, Bjarne
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Garvare, Rickard
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Eriksson, Henrik
    Chalmers University of Technology.
    Hallencreutz, Jacob
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Langstrand, Jostein
    Linköpings universitet.
    Vanhatalo, Erik
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Zobel, Thomas
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Alive and kicking – but will Quality Management be around tomorrow?: A Swedish academia perspective2012In: Quality Innovation Prosperity, ISSN 1335-1745, E-ISSN 1338-984X, Vol. 16, no 2, 1-18 p.Article in journal (Refereed)
    Abstract [en]

    The purpose of this article is to describe how Quality Management (QM) is perceived today by scholars at three Swedish universities, and into what QM is expected to develop into in twenty years. Data were collected through structured workshops using affinity diagrams with scholars teaching and performing research in the QM field. The results show that QM currently is perceived as consisting of a set of core of principles, methods and tools. The future outlook includes three possible development directions for QM are seen: [1] searching for a “discipline X” where QM can contribute while keeping its toolbox, [2] focus on a core based on the traditional quality technology toolbox with methods and tools, and [3] a risk that QM, as it is today, may seize to exist and be diffused into other disciplines.

  • 48.
    Bergquist, Bjarne
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Söderholm, Peter
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Measurement System Analysis of Railway Track Geometry Data using Secondary Data2016Conference paper (Refereed)
    Abstract [en]

    In this paper, we use secondary data to make a partial measurement system analysis of railway measurement cars and their obtained track geometry data. When a measurement car passes the same track section shortly after the previous passage, such as returning in the other direction after reaching a railway endpoint, the repeated measurements hold information of the measurement uncertainty of that car. Reasons for the measurement uncertainty can be sought in other variables that also are stored in the database, such as the individual car identity, the type of car, the speed of the car during measurement, and the travelled direction of the car. By also considering other known factors during the time of measurement as regressors, such as ground frost periods, enhanced modelling may be achieved and also indicate if such periods should be avoided to improve the measurement data quality.The results of this study suggest that the type of car had the largest influence on measurement variation out of the studied regressors. If the variation of a track geometry property on a track section is studied, the variation component belonging to the type of car can be deducted, improving data quality. We suggest that the method could also be used to find track sections that are prone to large seasonal variation, such as due to ground frost.

  • 49.
    Bergquist, Bjarne
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Söderholm, Peter
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Measurement Systems Analysis of Railway Measurement Cars2016Conference paper (Refereed)
    Abstract [en]

    Purpose: The presentation proposes ways to understand and quantify the variation component due to the measurement system of railway track properties using subsequent runs from measurement cars.Background: Railway infrastructure conditions are commonly inspected by using measurement cars. The measurements are performed with some regularity, and the inspection frequencies could for instance be set taking into account the common train axle loads, railway speed or load bearing classification, number of trains passing, the known railway condition, or the availability of the measurement cars. By combining different inspections of the same track section, it is also possible to monitor the degradation of the infrastructure over time. Often, the railway system is inspected by many measurement cars, and for single tracks, measurements can be obtained from the car travelling in different directions. The measurements are performed at different speeds, related to random variation, but also to the maximum speeds at which the measurement cars operate. The measurements are also afflicted by external variation sources, some of which are acting with a known direction, such as the wear of the track which increases property variation. Maintenance usually (but not always) result in reduced property variation, whereas other sources such as climate related properties such as spring thaw may induce variation over time, but also induce variation that show a periodic behavior with periods with increasing as well as decreasing property variation. This presentation aims to devise a model for how these variation sources may be separated, with the main aim to classify measurement error, but also to estimate the magnitude of other variation sources.Method: No statistically significant differences were found between repeated measurements of cars travelling back and forth on the single track found at the Swedish Iron ore line. These measurements contain measurement error as well as error due to short term degradation and variation due to measurement. As measurement variance is added, it was concluded that the measurement variation could not be larger than the variation shown by repeat measurements. By comparing repeated measurements over time and subtracting variation due to wear, measurement variation for different cars, measurement speeds and measurement directions was estimated using Generalized Linear Models regression analysis. Co-variation between measurement cars and measurement speeds were accounted for using Ridge regression and Elastic Net regression.Results: The regression analysis shows that whereas both measurement speed and the measurement car individuals correlate with the measurement variation obtained, regularized regression points to the measurement cars as the major variation factor and that different measurement cars have different measurement precisionDiscussion and conclusion: The study demonstrates how repeated measurements from regular process data and thus not obtained using the regular and systematic experimental procedures of measurement system analysis can be used for estimation of the variation components of the measurement system. As a side effect, the sizes of other variation sources, external to the measurement system, can be estimated.

  • 50.
    Bergquist, Bjarne
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Söderholm, Peter
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Data Analysis for Condition-Based Railway Infrastructure Maintenance2015In: Quality and Reliability Engineering International, ISSN 0748-8017, E-ISSN 1099-1638, Vol. 31, no 5, 773-781 p.Article in journal (Refereed)
    Abstract [en]

    Condition assessment is crucial to optimize condition-based maintenance actions of assets such as railway infrastructure, where a faulty state might have severe consequences. Hence, railways are regularly inspected to detect failure events and prevent the inspected item (e.g. rail) to reach a faulty state with potentially safety critical consequences (e.g. derailment). However, the preventive measures (e.g. condition-based maintenance) initiated by the inspection results may cause traffic disturbances, especially if the expected time to a faulty state is short. The alarm limits are traditionally safety related and often based on geometrical properties of the inspected item. Maintenance limits would reduce the level of emergency, producing earlier alarms and increasing possibilities of planned preventive rather than acute maintenance. However, selecting these earlier maintenance limits in a systematic way while balancing the risk of undetected safety-critical faults and false alarms is challenging. Here, we propose a statistically based approach using condition data of linear railway infrastructure assets. The data were obtained from regular inspections done by a railway track measurement wagon. The condition data were analysed by a control chart approach to evaluate the possibility for earlier detection of derailment hazardous faults using both temporal and spatial information. The study indicates that that the proposed approach could be used for condition assessment of tracks. Control charts led to earlier fault warnings compared to the traditional approach, facilitating planned condition-based maintenance actions and thereby a reduction of track downtime

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