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  • 1.
    Adamson, Göran
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Wang, Lihui
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Production Engineering, Royal Institute of Technology, Stockholm, Sweden.
    Moore, Philip
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Feature-based control and information framework for adaptive and distributed manufacturing in cyber physical systems2017In: Journal of manufacturing systems, ISSN 0278-6125, E-ISSN 1878-6642, Vol. 43, p. 305-315Article in journal (Refereed)
    Abstract [en]

    Modern distributed manufacturing within Industry 4.0, supported by Cyber Physical Systems (CPSs), offers many promising capabilities regarding effective and flexible manufacturing, but there remain many challenges which may hinder its exploitation fully. One major issue is how to automatically control manufacturing equipment, e.g. industrial robots and CNC-machines, in an adaptive and effective manner. For collaborative sharing and use of distributed and networked manufacturing resources, a coherent, standardised approach for systemised planning and control at different manufacturing system levels and locations is a paramount prerequisite.

    In this paper, the concept of feature-based manufacturing for adaptive equipment control and resource-task matching in distributed and collaborative CPS manufacturing environments is presented. The concept has a product perspective and builds on the combination of product manufacturing features and event-driven Function Blocks (FB) of the IEC 61499 standard. Distributed control is realised through the use of networked and smart FB decision modules, enabling the performance of collaborative run-time manufacturing activities according to actual manufacturing conditions. A feature-based information framework supporting the matching of manufacturing resources and tasks, as well as the feature-FB control concept, and a demonstration with a cyber-physical robot application, are presented.

  • 2.
    Almqvist, Josefin
    et al.
    University of Skövde, School of Technology and Society.
    Sundelius, Emma
    University of Skövde, School of Technology and Society.
    Modular Locking System to RBS Cabinet2013Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Radio base stations contain equipment which enables the use of cell phones all around the world. ERICSSON is developing these stations and everything connected to the area, such as electronics, software and hardware. In a new project ERICSSON plans to make their hardware modular, to satisfy all their customers around the world even if their preferences differ. The task that was given to us was to develop a modular locking system to the radio base station cabinets.The concept was developed in an integrated working process that focused on a user centered final product. The process included the definition of the problem, preliminary studies of areas which are connected to the problem and a summary of the demands that the customers mediated in a list of requirements. The idea generation generated lots of ideas that later on were developed into different concepts. The concepts were evaluated before the final decision was made together with ERICSSON.The final product is a lifting handle connected to a rod and latch system, which already existed. A new mechanical function was created to make the new handle function with the old system. The locking system is modular and it is possible to choose which way to lock the handle, with a cylinder lock or a padlock. Only one module, the cylinder in the middle, needs to be switched to get the other solution. The other parts are the same; this makes the product modular. The lift handle is an entire new design, developed in the project.

  • 3.
    Andersson, Johanna
    et al.
    University of Skövde, School of Technology and Society.
    Thyberg, Terese
    University of Skövde, School of Technology and Society.
    Chefsrekrytering: Hur fungerar det?2007Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Recruitment can include everything from hiring a stand-in for the summer to finding an executive for a big company. When hiring an executive is it important for the company that the right person gets the right job. There is little information in Swedish literature that explains how executive recruitment separates from ordinary recruitment. Neither is there any information about how internal and external executive recruitment are separated.

    When a recruitment process starts it is important to do a thorough preparatory work. This can be done by doing a work analyse, or a revision of the job description which is mostly used in executive recruitment. After this a specification of requirements is formed, the specification is a guide that the company uses to specify what kind of person they want to hire.

    The search of candidates for a position can be done in several different ways. The company has to decide if they should do the process by themselves or if a recruitment firm should be consulted, which is common today. There are several ways of searching candidates, the most common today is advertising in different media or using the employment service. The company also have to make a decision considering if the search should be done internal or external, or both ways.

    When suitable candidates have been chosen it is time for interviews and testing. At this time the recruiter meets the candidate for the first time and creates a picture of him or her. Testing is often used as a complement to the interview to confirm or deny feelings or suspicions that has arisen during the process. Another way of doing this is by contacting references, it is important to be aware of the fact that references often just have good things to say about the candidate. There is a risk with this considering that the whole truth might not come out.

    There are many different ways of making the decision who to hire, most important is though to use the specification of requirements as basic data. It is not always a need that all demands in the specifications are fulfilled, the candidates other qualifications can be more important.

    During this study it has come to our knowledge that the recruitment process for hiring executives are not that different from the process of hiring other co-workers. The biggest difference is that companies often choose to outsource the process to a consult. The companies in this study are quite small and think that they don’t have the right competence to find people with the right qualifications themselves. They think that it is better to pay money to the consultant than risk that the recruitment goes wrong and they have to do the process all over again.

    Companies today are more interested in recruiting executives from outside the company. In a time of changes they want an objective point of view to be able to survive in business. Once again there are no right or wrong way for the company to choose, but to search both internal and external might be the best solution to minimize the risk of overlooking the best candidate. Being able to advance in the company is a big push for many employees to work harder.

  • 4.
    Andersson, Marie
    et al.
    University of Skövde, School of Technology and Society.
    Fredricsson, Sandra
    University of Skövde, School of Technology and Society.
    Effektivitetsmätning: En studie kring privata företags inre effektivitet2007Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Effektivitetsmätning är ett ständigt aktuellt ämne som intresserar många företag. Historiskt sett har denna mätning begränsats till ekonomiska aspekter, men i dagens samhälle räcker inte det. För att hänga med i den allt hårdare konkurrensen mellan företagen måste effektivitetsmätningen täcka upp organisationens samtliga aktiviteter. Utifrån teorier om effektivitet, mål och mått har det därför undersökts hur privata företag arbetar med den inre effektivitetsmätningen, samt hur detta kan appliceras på tjänste- och systemutvecklingsföretaget Aptic AB.

    Denna kvalitativa studie baseras på sju intervjuer genomförda på olika företag som alla har använt sig av effektivitetsmätningar i flera år. För att få en överblick av Aptic AB:s behov av liknande effektivitetsmätningar intervjuades även två personer från denna organisation. Intervjuerna var halvstrukturerade med öppna frågor för att respondenterna skulle ha möjlighet att ta upp det som de själva tyckte var viktigt.

    Empirin visar att effektivitet kan mätas genom att sätta upp mål inom områden som ekonomi, kvalitet, leveranssäkerhet, medarbetare, säkerhet, miljö och förbättringar, för att sedan utföra mätningar som visar hur verksamheten ligger till i förhållande till det. Eftersom samtliga företag ansåg att effektivitetsmätning är en viktig del i organisationens överlevnad på längre sikt, så rekommenderas även Aptic AB att påbörja detta arbete.

  • 5.
    Aslam, Tehseen
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Bandaru, Sunith
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Multi-objective Optimization and Analysis of the Inventory Management Model2014In: Proceedings of the 2014 Summer Simulation Multiconference, Society for Computer Simulation International , 2014, Vol. 46, p. 99-106Conference paper (Refereed)
  • 6.
    Aslam, Tehseen
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Karlsson, Ingemar
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Integrating system dynamics and multi-objective optimisation for manufacturing supply chain analysis2014In: International Journal of Manufacturing Research, ISSN 1750-0605, Vol. 9, no 1, p. 27-57Article in journal (Refereed)
    Abstract [en]

    The aim of this paper is to address the dilemma of supply chain management (SCM) within a truly Pareto-based multi-objective context. This is done by introducing an integration of system dynamics and multi-objective optimisation. An extended version of the well-known pedagogical SCMproblem, the Beer Game, originally developed at MIT since the 1960s, has been used as the illustrative example. As will be discussed in the paper, the integrated multi-objective optimisation and system dynamics model has been shown to be very useful for revealing how the parameters in the Beer Game affect the optimality of the three common SCM objectives, namely, the minimisation of inventory cost, backlog cost, and the bullwhip effect.

  • 7.
    Aslam, Tehseen
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H.C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Strategy evaluation using system dynamics and multi-objective optimization for an internal supply chain2015In: Proceedings of the 2015 Winter Simulation Conference / [ed] L. Yilmaz, W. K. V. Chan, I. Moon, T. M. K. Roeder, C. Macal and M. D. Rossetti, Piscataway, NJ, USA: IEEE Press, 2015, p. 2033-2044Conference paper (Refereed)
    Abstract [en]

    System dynamics, which is an approach built on information feedbacks and delays in the model in order to understand the dynamical behavior of a system, has successfully been implemented for supply chain management problems for many years. However, research within in multi-objective optimization of supply chain problems modelled through system dynamics has been scares. Supply chain decision making is much more complex than treating it as a single objective optimization problem due to the fact that supply chains are subjected to the multiple performance measures when optimizing its process. This paper presents an industrial application study utilizing the simulation based optimization framework by combining system dynamics simulation and multi-objective optimization. The industrial study depicts a conceptual system dynamics model for internal logistics system with the aim to evaluate the effects of different material flow control strategies by minimizing total system work-on-process as wells as total delivery delay.

  • 8.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    An empirical comparison of metamodeling strategies in noisy environments2018In: Proceedings of the Genetic and Evolutionary Computation Conference (GECCO-2018) / [ed] Hernan Aguirre, New York, NY, USA: ACM Digital Library, 2018, p. 817-824, article id 3205509Conference paper (Refereed)
    Abstract [en]

    Metamodeling plays an important role in simulation-based optimization by providing computationally inexpensive approximations for the objective and constraint functions. Additionally metamodeling can also serve to filter noise, which is inherent in many simulation problems causing optimization algorithms to be mislead. In this paper, we conduct a thorough statistical comparison of four popular metamodeling methods with respect to their approximation accuracy at various levels of noise. We use six scalable benchmark problems from the optimization literature as our test suite. The problems have been chosen to represent different types of fitness landscapes, namely, bowl-shaped, valley-shaped, steep ridges and multi-modal, all of which can significantly influence the impact of noise. Each metamodeling technique is used in combination with four different noise handling techniques that are commonly employed by practitioners in the field of simulation-based optimization. The goal is to identify the metamodeling strategy, i.e. a combination of metamodeling and noise handling, that performs significantly better than others on the fitness landscapes under consideration. We also demonstrate how these results carry over to a simulation-based optimization problem concerning a scalable discrete event model of a simple but realistic production line.

  • 9.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    On the scalability of meta-models in simulation-based optimization of production systems2015In: Proceedings of the 2015 Winter Simulation Conference / [ed] L. Yilmaz, W. K. V. Chan, I. Moon, T. M. K. Roeder, C. Macal, and M. D. Rossetti, Piscataway, NJ: IEEE Press, 2015, p. 3644-3655Conference paper (Refereed)
    Abstract [en]

    Optimization of production systems often involves numerous simulations of computationally expensive discrete-event models. When derivative-free optimization is sought, one usually resorts to evolutionary and other population-based meta-heuristics. These algorithms typically demand a large number of objective function evaluations, which in turn, drastically increases the computational cost of simulations. To counteract this, meta-models are used to replace expensive simulations with inexpensive approximations. Despite their widespread use, a thorough evaluation of meta-modeling methods has not been carried out yet to the authors' knowledge. In this paper, we analyze 10 different meta-models with respect to their accuracy and training time as a function of the number of training samples and the problem dimension. For our experiments, we choose a standard discrete-event model of an unpaced flow line with scalable number of machines and buffers. The best performing meta-model is then used with an evolutionary algorithm to perform multi-objective optimization of the production model.

  • 10.
    Bernedixen, Jacob
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Volvo Car Corporation, Gothenburg, Sweden.
    Antonsson, Tobias
    Volvo Car Corporation, Gothenburg, Sweden.
    Simulation-based multi-objective bottleneck improvement: Towards an automated toolset for industry2015In: Proceedings of the 2015 Winter Simulation Conference / [ed] L. Yilmaz, W. K. V. Chan, I. Moon, T. M. K. Roeder, C. Macal, and M. D. Rossetti, Press Piscataway, NJ: IEEE Press, 2015, p. 2183-2194Conference paper (Refereed)
    Abstract [en]

    Manufacturing companies of today are under pressure to run their production most efficiently in order to sustain their competitiveness. Manufacturing systems usually have bottlenecks that impede their performance, and finding the causes of these constraints, or even identifying their locations, is not a straightforward task. SCORE (Simulation-based COnstraint REmoval) is a promising method for detecting and ranking bottlenecks of production systems, that utilizes simulation-based multi-objective optimization (SMO). However, formulating a real-world, large-scale industrial bottleneck analysis problem into a SMO problem using the SCORE-method manually include tedious and error-prone tasks that may prohibit manufacturing companies to benefit from it. This paper presents how the greater part of the manual tasks can be automated by introducing a new, generic way of defining improvements of production systems and illustrates how the simplified application of SCORE can assist manufacturing companies in identifying their production constraints.

  • 11.
    Calestam, Magnus
    et al.
    University of Skövde, School of Technology and Society.
    Wedin, Johan
    University of Skövde, School of Technology and Society.
    Bucklingsanalys av spannmålssilo2013Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Grains with varying humidity can be stored in square silos with wall elements consisting of corrugated sheet. When the stored grain is to be emptied from the silos it has tendency to stick to the walls, especially if humid, which means that the grain must be removed manually. To avoid this time-consuming process a flat sheet is mounted on the corrugated sheet to prevent the moist grain from sticking to the wall. If the same dimension on the corrugated sheet is used when the flat sheet is or is not mounted the walls may be subjected to buckling. This thesis is thus about how the wall elements shall be designed in order to prevent buckling. The silos that have been examined have a cross section of 3.0 x 3.0 m and 2.5 x 2.5 m respectively with wall elements consisting of only corrugated sheet or smooth sheet mounted on corrugated sheet. Furthermore, the silos got vertical walls with a height of 8.4 m consisting of ten sections. Calculations are made with wheat as the stored grain.

     

    To be able to dimension the wall elements the pressure is calculated for the different silos, using the Swedish and European standard Eurocode (2006), EN 1991-4 for pressure calculations in silos and tanks. To calculate the pressure the silos are assigned into action assessment class 1, since their capacity are less than a 100 tons, which further means that the unsymmetrical pressure can be ignored. The silos are also classified as slender. As the silos outlet consists of a square pyramidal hopper with centric outlet and a half internal angel of 45° an inner pipe flow occurs during emptying. This means according to Eurocode that the dimension shall be based on the pressure which occurs during filling. The horizontal and vertical pressure and the pressure made from the friction are calculated for the different cross sections.

     

    The CAD software Pro Engineer and the finite element extension Mechanica is used to model the current silos and perform analysis for stress and buckling. The models have four symmetry planes therefore only one eighth of the current structure is modeled, corresponding to half a wall element and half a pole. The models are created as shell models and boundary conditions are applied in all symmetrical planes and on the top and bottom of the pole. The structure of the silos is simplified since no screws or radius is modeled. The pressure calculated according to Eurocode is converted into forces and applied to the models. The whole structure is modeled in steel with yield strength of 180 MPa.

     

    The company’s older dimension standards are applied on the wall elements and analyzed. To investigate where to most critical areas for buckling occurs a buckling analysis based on a static analysis of the models is performed. The results from the buckling analysis for the silo wall element consisting of corrugated sheet with the width of 3.0 m shows that buckling occurs on the second bottom section at 72 % of the applied force. For the silo consisting of the same wall element but with the width of 2.5 m buckling occurs at the top section where the buckling force amounts to 62 % of the applied force. For the silos with wall elements consisting of plain sheet mounted on corrugated sheet buckling occurs at 3-4 % of the applied force for the two wall widths. Analysis show that the low values of buckling load on the plane sheet is a result from local buckling. In order to dimension the corrugated sheet to prevent it from buckling when the plane sheet is mounted a free body diagram is made for the corrugated sheet to obtain the acting forces. The buckling analysis of the corrugated sheet, with wall width 3.0 m, which is pressurized by the plane sheet shows that buckling occurs on the silos second bottom section. Buckling occurs at 59 % of the applied force for the silo with wall width of 2.5 m buckling occurs at 51 % of the applied force on the silo top section.

     

    Since the goal is that the corrugated sheets are not to be subject to buckling, the thickness of the sheets is iterated until the buckling force is equal to at least 110 % of the applied force. This generates an increased thickness for the lower four sections for the silo with wall element consisting of corrugated sheet with wall width of 3.0 m. For the silo with the same wall elements but with a wall width of 2.5 m, the dimensions of the top two sections need to increase. Regarding the silos with wall elements consisting of plane sheet mounted on corrugated sheet an increase in dimension is needed for the corrugated sheet for the five lowest sections for the wall width of 3.0 m.

     

    With a wall width of 2.5 m the same dimension can be used as when the silo wall elements consist of only corrugated sheet. If the plane sheet is not to be exposed for buckling the thickness of the sheets needs to be increased from between 5.5 mm and 1.5 mm. All calculations of the sheet dimensions are obtained by a conservative thinking which means that the company’s older dimensions may be correct. However, the resulting dimensions are reasonable for the corrugated sheets.

     

  • 12.
    Carrera Artola, Iosu
    et al.
    University of Skövde, School of Engineering Science. Mondragon Unibertsitatea.
    Lucena Garcerán, Alejandro
    University of Skövde, School of Engineering Science. University of Málaga .
    Detection of Frazil Ice at Water Intakes at Träbena Power Station2014Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Frazil ice is a phenomenon that takes place in cold regions when the water of rivers, lakes or oceans is cooled under 0ºC. Several times during winter, frazil ice can appear at river Ätran, where Träbena hydropower plant is held by the company Wetterstad Consulting AB. Frazil ice particles contained in the flowing water are extremely sticky and adhere to any object placed in the water. Trash racks are used by the power plant at the water intakes to prevent any strange object to go into the turbines. However, frazil ice particles stick to the trash racks creating an ice blockage that interrupts the water inflow. In this situation, the power plant has to stop the production even for several months, due to the lack of water that reaches the turbines. In order to solve this problem, the company has installed a heating system on the trash racks that prevent the adhesion of frazil ice particles. This system is manually operated, and it is turned on or off based on the experience and predictions of the company. This heating system is very power consuming and every time it is turned on unnecessarily the company loses money. An automatic frazil ice detection system that turns on the heating system when needed is to be created. For that, several options have been analysed, and finally a capacitor-based sensor has been developed as a solution. The sensor consist of two steel plates coated with semi-transparent polycarbonate submerged underwater parallel placed in the space between the trash racks’ bars, forming this way a parallel plate capacitor. The capacitance of a capacitor depends exclusively on its geometry and the dielectric material between the plates. Hence when the water temperature is low enough, frazil ice particles stick to the plates of the capacitor and its capacitance will vary indicating that the accretion of frazil ice may block the water inflow. This variation is registered and a signal is send to the heating system to start operating. This way, the heating system is completely automated; no human intervention is needed at all.

  • 13.
    Cámara Vela, Juan Antonio
    et al.
    University of Skövde, School of Engineering Science.
    Sánchez Molina, Juan Manuel
    University of Skövde, School of Engineering Science.
    Design of a Double Cantilever Beam Test Specimen and Fixture for Kink Band Formation in Unidirectional Fibre Reinforced Composites.2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Composite materials are widely used in demanding applications in aerospace and other industries. In order to understand the complex behaviour of the composite materials and their components, standardised test methods are used. One example is the double cantilever beam (DCB) test in which the test specimen is loaded in an opening, i.e., tensile mode. Failures in composite materials loaded compression are different from those in tension, for example, kink band or buckling-like failures can occur.

    In this project, several DCBs are designed and a new fixture which allows for compression testing of a DCB is developed for an existing Instron testing machine. The fixture overcomes a known problem of tensile peak causing the failure of the adhesive at the inner surfaces of the DBC by applying additional compressive loads along the outer surfaces of the DBC. The compressive forces can induce the desired kink band formation so that researchers can better study the failure mode.

    The conceptual development of the new DCBs and the new fixture are presented. Several prototypes of the specimens and the fixture are modelled using the three-dimensional (3D) computer-aided design software Creo Parametric 2.0.  One of the fixtures is selected to further study. The different DCB specimens are studied in order to obtain information about the kink band using 3D finite element analysis with the software programme Abaqus CAE. The selected fixture is analysed to determine if there are any areas of concern. Finally, the behaviour of the compression stress along the DCB using two pairs of forces is studied.

    Unfortunately, it is determined that the tensile peak experienced by the adhesive cannot be eliminated by the application of two pairs of compressive loads, one at the free end and the other in the vicinity of the tensile peak. Several suggestions are made for future work which might serve to reduce the tensile peak; e.g., the movable force couple is applied as a surface load instead of a point load. For this, the fixture will have to be modified with a new geometry, although the DCB could be the same. This will allow further work to focus on the combined behaviour of the tensile peak and the fixture.

  • 14.
    Fornlöf, Veronica
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. GKN.
    Sandberg, Ulf
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Almgren, Torgny
    GKN Aerospace Engine Systems.
    More reliable aircraft engine maintenance optimization by a classification framework for on-condition parts2014In: Proceedings of the 6th Swedish Production Symposium, SPS14, Gothenburg, Sweden, Chalmers , 2014Conference paper (Refereed)
  • 15.
    Frantzén, Marcus
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Production simulation education using rapid modeling and optimization: Successful studies2015In: Proceedings of the 2015 Winter Simulation Conference / [ed] L. Yilmaz, W. K. V. Chan, I. Moon, T. M. K. Roeder, C. Macal, and M. D. Rossetti, Piscataway, NJ: IEEE Press, 2015, p. 3526-3537Conference paper (Refereed)
    Abstract [en]

    A common issue facing many simulation educators is that students usually spend excessive time to struggle with the programming and statistic parts of the simulation courses, and simply very little time to learn running systems analysis. If the students are coming from industry, and not the campus, then the problem becomes even worse. We observed this problem around 2005 and started to develop a new simulation software, a factory conceptual design toolset, partly aimed to address this problem. A new set of educational courses has since then been developed around the software for teaching production systems analysis, with both the campus students and managers/engineers from industry in mind. In this paper, we briefly introduce the software and share our experiences and some representative, successful studies conducted by the students in the past years.

  • 16.
    Gastañares, Xabier
    et al.
    University of Skövde, School of Engineering Science.
    Bastida, Iñaki
    University of Skövde, School of Engineering Science.
    Evaluation of virtual confidence: turn-table model & mechatronic concept designer2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This work presents an evaluation of the virtual confidence that can be achieved in the software Mechatronic Concept Designer. The virtual confidence is defined as the reliability that a model or software offer, based on their capacity to replicate reality accurately. Reference system for the evaluation is a turn table used at AB Volvo in the production of front lids. After conducting the simulations and different kind of analyses (such as friction analyses), the main conclusion has been that both the original model and the software offered some limitations that made a high level of virtual confidence impossible. Taking into account this fact, future improvement lines have been suggested. 

  • 17.
    Gudfinnsson, Kristens
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Strand, Mattias
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    On transforming into the data-driven decision-making era: current state of practice in manufacturing smes2018In: Advances in Manufacturing Technology XXXII: Proceedings of the 16th International Conference on Manufacturing Research, incorporating the 33rd National Conference on Manufacturing Research, September 11–13, 2018, University of Skövde, Sweden / [ed] Peter Thorvald, Keith Case, Amsterdam: IOS Press, 2018, Vol. 8, p. 337-342Conference paper (Refereed)
    Abstract [en]

    Current research lacks details on how SMMEs are able to capitalize on how their IT-solutions supports data-driven decision-making. Such details are important for being able to support further development of SMMEs and assuring their sustainability and competitive edge. Prosperous SMMEs are vital due to their economical and societal importance. To alleviate the lack of details, this paper presents the results of four case studies towards SMMEs partly aimed at investigating their current state of data-driven decision-making. The findings reveal that IT-solutions in some areas are either underdeveloped or unexplored. Instead, the SMMEs tend to focus on traditional manufacturing techniques, continuous improvements in the manufacturing process, and manual support routines and thereby neglects opportunities offered in relation to e.g. incident management, product quality monitoring, and the usage of KPIs not directly linked to manufacturing.

  • 18.
    Hugo, Perea Lisbona
    University of Skövde, School of Technology and Society.
    Bachelor Degree Project: Suitcase for Laptop Computer with integrated cooling system and workstation functionality2007Student thesis
    Abstract [en]

    This report summarizes a Bachelor Degree Project in Product Design Engineering,

    carried out during the spring semester in 2007 by one student on the Product Design

    Engineering programme at University of Skövde. The project was performed as an

    assignment for Comfort Cooling AB, a company in Skövde that manufactures cooling

    clothes and products for medical use.

    The purpose of the project is to design a suitcase for laptops that is used also as a

    workstation. It has a cooler system, provided by Comfort Cooling that works with no

    external energy. It has a base made of foam sheet, to adapt it to the legs of the user. And it

    has as well all the normal features characteristically of a suitcase for laptops, such as

    pockets, handles and security features.

    The first step in the project was to perform market research in order to gather

    customer needs. It was found that the primary features of a laptop suitcase are that it is

    waterproof, that it is possible to carry the suitcase on ones back, that there are trays on both

    sides of the suitcase, and that the suitcase will be available in a range of patterns and

    colours. After that, the design of the possible solutions for each requirement started to be

    developed. Once all the requirements of the project were satisfied with different solutions,

    each one of them were evaluated in order to identify the solutions that in the best way met

    the stated product requirements. Finally a mock-up was produced for communicating the

    final design proposal and for enabling basic user trials to be carried out, as well as the final

    result, i.e. the design and the mock-up of the laptop suitcase.

    The report portrays the product design process and methods utilized in the project,

    as well as the final result (the mock up) of the laptop computer bag with integrated cooling

    effect and workstation.

  • 19.
    Junefjäll, Johan
    et al.
    University of Skövde, School of Technology and Society.
    Bäckerstam, Valentina
    University of Skövde, School of Technology and Society.
    Livscykelanalys: Pelletspanna från kvänum energi2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This study will identify the environmental impact in terms of carbon dioxide for a boiler house on behalf of Kvänum energi. The boiler central consists of a main building, which in turn contains multiple components such as boilers, pipes, etc, the boiler central uses pellets fuel. It also includes a silo and an ash container. The total weight of the boiler is about 63 tons. Each boiler has an output of 600 kW; the central includes three boilers with room for a fourth if necessary. The study has followed the ISO 14040 as far as it has been possible. The boiler central is manufactured at Kvänum Energi’s plant in Kvänum and then assembled on-site for the customer. When analyzing the system the entire product has been divided into smaller parts to make the analysis more manageable. The breakdown was made regarding the material. The conclusions from the calculations of emissions were that material was of greater importance to the environment than transportation. Design improvement proposal was mainly focused on materials and how any change of material would affect the environment and energy consumption. The ability to construct the building and silo in aluminum was investigated from the strength, price and environmental impact point of views. From design point of view, steel and aluminum are equivalent for the purpose, but in terms of cost, aluminum is more expensive. However the recycling option is significantly better for aluminum. EPS (Environmental Priority Strategies), which is a Swedish method developed for engineers at Volvo, was used for the calculation of environmental impact. When comparing steel and aluminum, the aluminum construction received a lower value regarding carbon dioxide i.e. better from an environmental perspective. The study includes a short survey on a transport to a fossil fuel dependent country, and it is investigated whether such a transport would be justified. The transport would be by boat and truck and the resulting emissions from the transport is about 1 ton of CO2. In the study, Lithuania has been chosen as an example because it has the same climate as in Sweden, i.e. a large need for heating during winter, and also because that Lithuania has a high dependence of oil and gas for heating.

  • 20.
    Jönsson, Martin
    University of Skövde, School of Engineering Science.
    Utveckling av hanteringslösning för processat avloppsslam på boendeplattformar i offshore industrin2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This product development project has been carried out in cooperation with the company, Pegil Innovations AB. The purpose of the project was to develop a management solution for processed sewage sludge (dust) on accommodation vessels in the offshore industry. The process of the project combined the Front-End process with details from Set-Based Concurrent Engineering.

    The project started with a preliminary study and user studies to obtain deeper understanding regarding the relevant knowledge area. Details that were of importance to the project was gathered in a specification that was used through the entire process as a support. Then an idea generation was preformed, to discover and explore different solutions. From the idea generation five different idea solutions were created. These five solutions were explored deeper and then compared to a new specification. The specification was an updated version from the first one to better reflect what conditions the idea solutions should meet. When the idea solutions were explored, a new idea generation was performed, resulting in two concepts. These concepts were explored deeper and then compared to a new specification. Then followed another idea generation to explore how the concepts could be improved.

    In conclusion to the project a concept was chosen. The result was a plastic bag which was fastened around a spigot, that was filled with the dust and then the air was withdrawn (to create a vacuum). Then the opening of the plastic bag was heat sealed. The personal could then easily carry the bag to discard this together with the dust.

  • 21.
    Khaki Boukani, Farzad
    University of Skövde.
    Overcoming logistical problems in organizations: The case of Elicom AB2007Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This paper presents an empirical case study of the company Elicom AB. Elicom AB is producing electrical devices that are mostly used in the telecom market where the main customers are. The data that was collected from this case was collected through observations, interviews and the study of company documents. This allowed the author to compare secondary and primary data, as well as quantitative and qualitative information. The problem, the company is facing in the logistical field, was discovered in the labeling production process.

    The production of the labels is unnecessarily complicated and inefficient due to incompatibility of the computer systems. Therefore some parts of the label design have to be made manually, even though the company has a scanning system. When analyzing the problem in detail it became clear to the author that it could be fixed easily and fast and that the key individuals involved in the process already knew the answer to the problem. Therefore the question of the underlying cause of the problem arose. Why has the company not yet fixed the problem if it is so obvious and also everybody in the organization is aware of it?

    When further reanalyzing the problem, the author discovered a second problem, which was not lying in the logistics of the production process, but had its roots in the organizational structure. The problem of interfering authorities and responsibilities made it impossible for the company to overcome the changes needed to solve the logistical problem in the labeling production process. Therefore this problem must be addressed first, together with overcoming the obstacles to change in the organization, to make a problem-solving-process in the logistical area possible.

    In general this paper shows the interrelation of logistics with organization and the highly complex environment manufacturing companies are facing when it comes to changes in the production process.

  • 22.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Towards strategic development of maintenance and its effects on production performance by using system dynamics in the automotive industry2018In: International Journal of Production Economics, ISSN 0925-5273, E-ISSN 1873-7579, Vol. 200, p. 151-169Article in journal (Refereed)
    Abstract [en]

    Managing maintenance within an economical short-termism framework, without considering the consequential long-term cost effect, is very common in industry. This research presents a novel conceptual system dynamics model for the study of the dynamic behaviors of maintenance performance and costs, which aims to illuminate insights for the support of the long-term, strategic development of manufacturing maintenance. By novel, we claim the model promotes a system's view of maintenance costs that include its dynamic consequential costs as the combined result of several interacting maintenance levels throughout the constituent feedback structures. These range from the applied combination of maintenance methodologies to the resulting proactiveness in production, which is based on the rate of continuous improvements arising from the root cause analyses of breakdowns. The purpose of using system dynamics is to support the investigations of the causal relationships between strategic initiatives and performance results, and to enable analyses that take into consideration the time delays between different actions, in order to support the sound formulation of policies to develop maintenance and production performances. The model construction and validation process has been supported by two large maintenance organizations operating in the Swedish automotive industry. Experimental results show that intended changes can have both short and long-term consequences, and that obvious and hidden dynamic behavioral effects, which have not been reported in the literature previously, may be in the system. We believe the model can help to illuminate the holistic value of maintenance on the one hand and support its strategic development as well as the organizational transformation into proactiveness on the other.

  • 23.
    Lundberg, Daniel
    et al.
    University of Skövde, School of Technology and Society.
    Mattsson, Tobias
    University of Skövde, School of Technology and Society.
    Klämskydd: Minimering av klämrisk2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    On behalf of the client, a design proposal regarding pinch protection is developed. This follows the recommendationsfrom Boverket to improve the pinch security in doors. The recommendations are based ona report by Konsumentverket. The report illustrates that approximately 50% of all the pinch related accidentshappens on the lock side of the door, while there are few solutions to minimize the risk of pinchingat the lock side.A product comparison is carried out to see what kind of solutions the market offers. Practical tests andobservations of door closure are performed.Concept development begins with the production of simple sketches. Inspiration to the pinch protectionsare taken from both students on the nearby engineering programs, family and friends as well as of variousvisits to retailers. In order to compare the different concepts, a balanced concept selection matrix is used.From a selection of six concepts three is chosen to go through further developed.Finally, one concept laid the foundation for a design proposal. The concept is based on a pinch protectionwith air cushioning, which is activated when someone forcefully try to close the door. Pinch protectionminimizes the risk of injury to the user between door leaf and the lock side of the door. A FEM-analysisis performed on the included parts to analyze the strength of materials. Function is tested by investigatingif compression occurs in the prototypes created. The tests show that compression occurs.The results of the thesis lead to a design proposal with accompanying drawings and materials. The designproposal should be mounted under the top edge of the frame. The pinch protection dampens the doorsmovement by using compression inside the chamber, at a slow movement no compression occurs, whichmeans that the door can be closed normally.The chambers and the piston rod can been made in zinc alloy ZA-27 if reconstruction is made before thecasting. A PVC elastomer is used for molding the damping plate, also a conic pressure spring and eightscrews for assembly are used.Construction of the proposals strength need to be reviewed to ensure adequate strength, as a future workthe FEM analysis shows that the material is exposed to very high tension.

  • 24.
    Martínez Conde, Sergio
    et al.
    University of Skövde, School of Engineering Science.
    Pérez Luque, Estela
    University of Skövde, School of Engineering Science.
    Exoskeleton for hand rehabilitation2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This document presents the development of a first proposal prototype of a rehabilitation exoskeleton hand. The idea was to create a lighter, less complex and cheaper exoskeleton than the existing models in the market but efficient enough to carry out rehabilitation therapies.The methodology implemented consists of an initial literature review followed by data collection resulting in a pre-design in two dimensions using two different software packages, MUMSA and WinmecC. First, MUMSA provides the parameters data of the movement of the hand to be done accurately. With these parameters, the mechanisms of each finger are designed using WinmecC. Once the errors were solved and the mechanism was achieved, the 3D model was designed.The final result is presented in two printed 3D models with different materials. The models perform a great accurate level on the motion replica of the fingers by using rotary servos. The properties of the model can change depending on the used material. ABS material gives a flexible prototype, and PLA material does not achieve it. The use of distinct methods to print has a high importance on the difficulties of development throughout the entire process of production. Despite found difficulties in the production, the model was printed successfully, obtaining a compact, strong, lightweight and eco-friendly with the environment prototype.

  • 25.
    Monge, Malco
    et al.
    University of Skövde, School of Technology and Society.
    Eriksson, Alexander
    University of Skövde, School of Technology and Society.
    Transporter från lastbil till järnväg: en fallstudie på Kährs2007Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Gustav Kährs AB is a company that is considering a change of transportation from trucks to railroad. Kährs headquarter is situated in Nybro. The company makes wooden floors and stores them in their central warehouse in Kalmar. Today all transports from the warehouse are carried out by trucks; the goods are then transported to the harbor in Helsingborg and then shipped to Bremen. Kährs is considering switching to railroad transportation between Kalmar and Helsingborg.

    The problem has been formulated as follows:

    “Is it worth to switch transportation method from tuck to railroad considering the following aspects: the environment, lead times, costs and investments?”

    To gain a deeper insight of the consequences that a switch would have on lead times, costs, investments and the environment we have chosen to conduct a case study. The purpose of this case study is not to reach a definitive answer to the problem but rather to give an open discussion on the subject. This fits our formulated problem fine, because the question if it is worth or not is a subjective matter.

    This thesis has been built around a model that consists of all the different aspects that have been mentioned within the formulated problem. From this model we have derived a calculation model to calculate if it is worth to make a switch from tucks to railroad from a cost perspective. From the calculation model we have further derived different scenarios were today’s situation is compared to alternative means of transportation involving railroad. The different scenarios include different harbors and investments like cranes, forklifts and extension of railroad.

    The calculation model focuses on the costs being generated by each scenario. The result of the analysis is that today’s truck solution had the most advantages compared to the other scenarios. But what final solution is chosen depends on what characteristics Kährs values. If the environment is an important factor, if Kährs feels that it is important to position itself as an environmental friendly company then the railroad would be an interesting alternative. The question is if Kährs is prepared to deal with the increased costs that this alternative generates. Perhaps the company doesn’t feel that the savings on the environmental side are reason enough to stand the extra costs.

    The answer to our formulated problem is that we don’t consider it worth shifting from tuck to railroad. But in the end it is all about what characteristics Kährs consider to be important.

  • 26.
    Ng, Amos H. C.
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Shaaban, Sabry
    Department of Strategy, ESC La Rochelle, La Rochelle, France.
    Bernedixen, Jacob
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Studying unbalanced workload and buffer allocation of production systems using multi-objective optimisation2017In: International Journal of Production Research, ISSN 0020-7543, E-ISSN 1366-588X, Vol. 55, no 24, p. 7435-7451Article in journal (Refereed)
    Abstract [en]

    Numerous studies have investigated the effects of unbalanced service times and inter-station buffer sizes on the efficiency of discrete part, unpaced production lines. There are two main disadvantages of many of these studies: (1) only some predetermined degree of imbalance and patterns of imbalance have been evaluated against the perfectly balanced configuration, making it hard to form a general conclusion on these factors; (2) only a single objective has been set as the target, which neglects the fact that different patterns of imbalance may outperform with respect to different performance measures. Therefore, the aim of this study is to introduce a new approach to investigate the performance of unpaced production lines by using multiple-objective optimisation. It has been found by equipping multi-objective optimisation with an efficient, equality constraints handling technique, both the optimal pattern and degree of imbalance, as well as the optimal relationship among these factors and the performance measures of a production system can be sought and analysed with some single optimisation runs. The results have illustrated that some very interesting relationships among the key performance measures studied, including system throughput, work-in-process and average buffer level, could only be observed within a truly multi-objective optimisation context. While these results may not be generalised to apply to any production lines, the genericity of the proposed simulation-based approach is believed to be applicable to study any real-world, complex production lines.

  • 27.
    Pehrsson, Leif
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Research and Technology Development, Engine Manufacturing Engineering, Volvo Car Group.
    Frantzén, Marcus
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aggregated line modeling for simulation and optimization of manufacturing systems2015In: Proceedings of the 2015 Winter Simulation Conference / [ed] L. Yilmaz, W. K. V. Chan, I. Moon, T. M. K. Roeder, C. Macal, and M. D. Rossetti, Piscataway, NJ, USA: IEEE Press, 2015, p. 3632-3643Conference paper (Refereed)
    Abstract [en]

    In conceptual analysis of higher level manufacturing systems, for instance, when the constraint on system level is sought, it may not be very practical to use detailed simulation models. Developing detailed models on supply chain level or plant wide level may be very time consuming and might also be computationally costly to execute, especially if optimization techniques are to be applied. Aggregation techniques, simplifying a detailed system into fewer objects, can be an effective method to reduce the required computational resources and to shorten the development time. An aggregated model can be used to identify the main system constraints, dimensioning inter-line buffers, and focus development activities on the critical issues from a system performance perspective. In this paper a novel line aggregation technique suitable for manufacturing systems optimization is proposed, analyzed and tested in order to establish a proof of concept while demonstrating the potential of the technique.

  • 28.
    Pettersson, Emil
    et al.
    University of Skövde, School of Engineering Science.
    Pettersson, Emil
    University of Skövde, School of Engineering Science.
    Utmattningsberäkning av hydraulikkopplingar: Metoder och beräkningar gällande utmattningsteorier2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to investigate the fatigue life of two components in different hydraulic quick couplings. The crack which initiates the fatigue failure usually occurs in the bottom of one of the threads. Thus, the threads in the coupling are carefully investigated. A few different approaches for determining the fatigue life are studied for each component. CAD (Computer Aided Design) models for both components are created and analyzed with FEM (Finite Element Method). By analyzing these components with FEM the stresses and the strains are calculated. These values for stress and strain are used to determine the fatigue life for the different components. The first component is suffering from high cycle fatigue. Four different approaches for high cycle fatigue are investigated. These four are Wöhler-curve, Haigh-diagram, von Mises fatigue criterion and Mises-Sines fatigue criterion. It was found that all of them but the von Mises fatigue criterion give a good approximation of the fatigue life. von Mises fatigue criterion does not consider the midstress, which can be a reason for this. The three other approaches indicate that the component will be suffering from fatigue, but will be relatively close to infinite life. The Wöhler-curve indicates that the component will withstand about 470 000 loading cycles. Compared to the experimental tests where the component withstands about 700 000 loading cycles, it can be said that the approach is a good estimation of the fatigue life. Approximated material data are used. For further work it is essential to obtain experimental material data for better approximation of the fatigue life. The second component is suffering from low cycle fatigue, which means that different approaches are needed. The approaches are originally from Coffin-Manson and Morrow. A total of four low cycle fatigue criterion have been studied. The first one is made by CoffinManson and takes the plastic strain in to account, the second is made by Morrow and takes both the elastic and the plastic strain in to account.  The third is a modification of Morrow’s criterion, and will consider the midstresses as well. The fourth is a simplification of Morrow’s criterion where more common material parameters are used. These four have been compared and it can be seen that the CoffinManson criterion gives the best approximation of the reality. The Coffin-Manson criterion gives an approximation of 50 000 loading cycles to fatigue failure which, compared to that the experimental tests suffered from fatigue failure after about 40 000 loading cycles, is a good estimation of the fatigue life.

  • 29.
    Popov Popov, Nikita
    University of Skövde, School of Engineering Science.
    Design and preliminary finite element analysis of structural frame of a double base for an infant child restraint system.2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Child restraint systems (CRS) are used for protection of the child in case of car accident. These systems have been found to have a difficult installation process that in many cases can cause greater loads on the child and as a consequence can lead to an increased risk of injury and a reduction in safety. The problems are even more significant in cases of families with two or more children and in small cars with lack of available space. Misuse and its causes are identified from literature as well as from surveys and market research. The design guidelines are gathered from existing CRS designs. Currently available automotive and CRS fastening systems are studied. A specific methodological approach is used for project development. A new concept for a child restraint system is introduced. The main aims are the design proposal of a double ISOFIX base for two children, reduction in the misuse of the CRS, improving the user experience and achieving technological, societal and environmental contributions. The second aspect is to verify the structure of the double base by means of preliminary finite-element analysis using the case of a frontal collision in accordance to current approval testing procedures. Al 2024 is chosen for design by the material selection performed in order to optimize the structure in relation to strength and weight. The finite-element preliminary static analysis is performed employing shell elements. The results are analysed with respect to the mesh convergence. In addition a linearized buckling check is carried out. Finally, the achieved results are discussed in comparison with initial assumptions and goals and future work is suggested.

  • 30.
    Sukia Garmendia, Alex
    et al.
    University of Skövde, School of Technology and Society.
    Echaniz Granado, Iñigo
    University of Skövde, School of Technology and Society.
    Design, Verification and Manufacturing of a New Binding System for Crampons2013Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Crampons are a device composed of a framework containing prongs, a front-part binding and a rear-part binding system that are attached to the boots in order to climb through steep walls covered by ice, snow or rocks. Currently, the process to attach the binding system is complicated and time consuming. A new design of the rear-part binding system of the step-in crampon adapted to the current boot is therefore desired to create. The Five-Step Method is implemented to obtain the concept design. The refinement of the concept is then performed and the mechanism is designed based on the action of a spring. This improvement provides a simpler and faster attachment process to the boot and it does not require removing the gloves. The steps for the new fastening and unfastening process are lowered compared to the step-in crampon. The Value Engineering Method is used when establishing the materials and manufacturing process of the components. Chromoly steel AISI 4130 is determined for the most critical components suffering highest stresses. High Density Polyethylene polymer is used for the parts with the lowest demands concerning the stresses they have to bear. These materials stand extremely low temperatures and provide low density and high tensile strength. Commercial elements are used when possible to reduce the costs and simplify the design and assembly process. A CNC milling machine is used to manufacture the steel pieces with simple shape. The moulding process for steels is established for the steel components with more complicated shapes. Injection moulding is determined to produce the polymer parts. A simple and effective process is established for the assembly of the elements, which does not required high ability or specific tools. The design of the assembly provides the opportunity to recycle the materials. The functionality of the attachment mechanism is proved. It is verified that the critical components withstand the stresses created at them according to a security factor of 4. This is concluded accomplishing an analytical analysis and also using the Finite Element Method. The cost of the new product is estimated to be more expensive than the reference step-in crampon. The designed product weights almost the same than the current step-in crampon and it has reduced dimensions for storing it. It includes a security system that avoids the binding system being released even if a high force is applied to the system. It is important to regulate the binding system to the height of the rear-part groove of the boot and to fasten the security system tightly to avoid any clearances between the boot and the crampon. 

  • 31.
    Sumic, Aldin
    et al.
    University of Skövde, School of Engineering Science.
    Slaattelia Larsson, Andrea
    University of Skövde, School of Engineering Science.
    UTVECKLING AV RÄDDNINGSUTRUSTNING FÖR SPINALSKADADE PATIENTER2014Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During the spring of 2014, Aldin Sumic and Andrea Slaattelia Larsson, two product design engineer students at University of Skövde carried out a product development project in cooperation with the company AB Germa. The aim of the project was to develop solutions to a conceptual "vacuum-scoop" by using Germas existing vacuum technology that is used to immobilize a patient with suspected spinal injury and integrate it into the existing scoop stretcher with its function to "scoop" a patient from the accident site. The aim of the project was also to reduce the number of patient transfers and to improve safety and quality in the rescue. One of Germas strategies, to compete on the market, is to launch two new products annually. Therefore, it was more desirable that, during the mission, bring out many ideas, gladly innovative ones, than get a fully functional solution in the end. The mission was carried out according to the product development methodology set based concurrent engineering to achieve this. Working with the methodology resulted that solutions were investigated and developed in parallel and were eliminated gradually if they, for some reason established deficiencies. The mission begins with a preliminary study and empirical data gathering, which included literature review, interviews and site visits to gain deeper knowledge of the subject. Using this, the functional analyzes and the standard EN-1865 the work was detailed and a set of requirements were made. Then an idea generation session started using various creative methods and complement. The drafts from the idea generation were of different character and quality. A selection session was used on a variety of ideas for distinguishing concepts which resulted in that the concept was excluded, grouped in terms of similarity or combine. Finally, there remained three working concept. The authors chose ignore the product development methodology to develop and detail design one of the three concepts for the final presentation - the concept that became known as the vacuumskop (vakuum scoop).

  • 32.
    Svenman, Edvard
    et al.
    GKN Aerospace Engine Systems, Trollhättan, Sweden / Engineering Science, University West, Trollhättan, Sweden.
    Christiansson, Anna -Karin
    Engineering Science, University West, Trollhättan, Sweden.
    Runnemalm, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Engineering Science, University West, Trollhättan, Sweden .
    Experimental validation of an inductive probe for narrow gap measurement based on numerical modelling2019In: Measurement, ISSN 0263-2241, E-ISSN 1873-412X, Vol. 146, p. 396-402Article in journal (Refereed)
    Abstract [en]

    Experimental validation of numeric results for an inductive probe shows that narrow gaps between two plates can be measured with accuracy suitable for laser beam welding. A two-coil inductive probe for measurement of the gap was built based on finite element modelling results. The individual coils were calibrated using a complex response method, and results from the physical coils closely match the numerical results regarding distance to gap and lift-off above the plate. The measurement of a realistic gap shows results that can be used in industrial applications for position, plate height and height alignment. 

  • 33.
    Svensson, Carl-Johan
    et al.
    University of Skövde, School of Technology and Society.
    Åkerstedt, Jesper
    University of Skövde, School of Technology and Society.
    Prognosprocessen: En fallstudie hos Asko Cylinda AB2007Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Balansering av tillgång och efterfrågan har alltid varit ett aktuellt ämne och för att klara av denna balansering krävs information om kommande efterfrågan. Denna information måste ligga så långt fram i tiden som det tar för att med säkerhet få hem exempelvis material. För att lyckas med detta använder sig företag i olika utsträckning av uppskattad framtida efterfrågan, så kallade prognoser. Prognoser kan definieras som systematiska metoder för att förutsäga framtida händelser.

    Problemet är att oavsett hur prognoser görs stämmer det prognostiserade värdet nästan aldrig överens med det verkliga utfallet. Många företag vet att deras prognoser inte är exakta utan att veta vad de ska göra åt saken. Många gånger ignorerar de bara problemet och hoppas att det ska lösa sig självt. För att kunna förbättra sina prognoser bör därför dokumentation och uppföljning ske av det arbete som görs. Med hjälp av uppföljning kan prognosfel beräknas, ett prognosfel är avvikelsen mellan det prognostiserade värdet och det verkliga utfallet. I de fall då prognosfelen är små kan företag genom dokumentation identifiera vad som urskilde dessa perioder från de med högre prognosfel.

    Författarna har i denna uppsats försökt beskriva hur företag kan uppnå en förbättrad prognosprocess med en lägre prognosavvikelse. Uppsatsen syftar också till att väcka intresset för samarbete över företagsgränser. Collaborative forecasting är en av metoderna som författarna har använt sig av för att överkomma problemen med traditionell prognostisering och som samtidigt är i linje med supply chain management. Denna metod samlar ihop och sammanställer information från både interna och externa källor för att sedan sammanställa en prognos som stöds av hela organisationen.

    Uppsatsen är en fallstudie hos vitvaruföretaget Asko Cylinda AB. För att få ytterligare idéer om hur prognosprocessen kan se ut i praktiken har författarna också tittat på prognosprocessen hos Volvo Penta AB. Båda företagens prognosprocesser har sedan analyserats och jämförts med hjälp av teori från litteratur och artiklar. Genom denna analys har författarna kommit fram till förslag på arbetssätt som Asko Cylinda AB och företag med liknande företagsmiljö kan använda sig av för att förbättra sin prognosprocess.

    Analyskapitlet är uppbyggt enligt tre scenarier, en nulägesbeskrivning, ett förslag på en enkel prognosprocess och ett förslag på en mer avancerad prognosprocess. I analysen har olika mätetal används för att åskådliggöra hur prognosavvikelsen varierar då till exempel olika prognosberäkningsmetoder används.

    Utifrån scenarierna som analyserats har författarna kommit fram till att det finns många fördelar med Asko Cylinda AB:s nuvarande arbetssätt och att flera av dessa stöds av teorin. En fördel med en enklare prognosprocess är att den allokerar betydligt mindre resurser än vad som görs i dagsläget. Detta är enligt författarna inte tillräckligt skäl att använda sig av den enkla varianten då framtiden går mot mer samarbete över företagsgränserna för att gemensamt öka konkurrenskraften. Arbetssättet som analyseras i scenario 3 ses av författarna som det bästa alternativet. Detta scenario har hämtat mycket inspiration från teorierna om collaborative forecasting, vilket bidrar till en process som arbetar mer enligt supply chain management. Även delar från både den nuvarande prognosprocessen och Volvo Penta AB:s prognosprocess har använts för att för att uppnå detta arbetssättsförslag som baserats på både teori och praktik och utformats för att vara slagkraftigt i framtiden.

  • 34.
    Syberfeldt, Anna
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Danielsson, Oscar
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Holm, Magnus
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Wang, Lihui
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Royal Institute of Technology, Stockholm, Sweden.
    Dynamic operator instructions based on augmented reality and rule-based expert systems2016In: Research and Innovation in Manufacturing: Key Enabling Technologies for the Factories of the Future - Proceedings of the 48th CIRP Conference on Manufacturing Systems / [ed] Roberto Teti, Elsevier, 2016, Vol. 41, p. 346-351Conference paper (Refereed)
    Abstract [en]

    Augmented reality is currently a hot research topic within manufacturing and a great potential of the technique is seen. In this study, we aim to increase the knowledge of the adaptation and usability of augmented reality for the training of operators. We propose an approach of using dynamic information content that is automatically adjusted to the individual operator and his/her learning progress for increased efficiency and shorter learning times. The approach make use of the concept of expert systems from the field of artificial intelligence for determine the information content on-line. We develop a framework called "Augmented Reality Expert System" (ARES) that combines AR and expert systems. A proof-of-concept evaluation of the framework is presented in the paper and possible future extensions are discussed.

  • 35.
    Tjus, Anna
    et al.
    University of Skövde, School of Technology and Society.
    Johansson, Annie
    University of Skövde, School of Technology and Society.
    A minor field study for combined rainwater andpond harvesting system and purification technology in the village Macedonia, Amazon basin, Colombia2008Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

     

    This study is a bachelor degree project which focuses on the lack of safe drinking water in a small village known as Macedonia in the Amazon basin in Colombia. The inhabitants of the village are 850 to the number and have never had access to safe drinking water. To solve this problem a system has been built where the rainwater is harvested in a pond and also from a church roof

    During the dry season the rainwater in the pond is harvested and pumped into sedimentation tanks. Thereafter, the water is led into the sand filtration tanks. While during the rain season, the rainwater is harvested from a church roof which is situated at highest level in Macedonia. The water is stored in a cistern and then it is led into sand filtration tanks via pipes. This means that the pond water and rainwater are never mixed before entering the filtration tanks.

    The sand filtration tanks contain about 1000 mm thick layer of sand and under it, a layer of gravel which is placed in the bottom of the tank. It takes a while for the water to be filtered through the sand filtration tank. Afterwards, it is led into the final tank, where the drinking water is stored ready to be used.

    The method of using slow sand filtration (SSF) is suitable for small scale-projects and therefore for this project a good idea for making drinking water. SSF requires no mechanical power or replaceable parts, this is why the technique is good for purifying water in developing and isolated areas.

    The result of the system is water with satisfied quality running through pipes and taps, ready to be consumed.

     

     

     

     

  • 36.
    Zetterberg, Stefan
    et al.
    University of Skövde, School of Technology and Society. University of Skövde, School of Technology and Society.
    Into, Camilla
    University of Skövde, School of Technology and Society.
    Transitlager som en strategi i ett globalt distributionssystem2009Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Nuförtiden är det stora flertalet försörjningskedjor internationella till sin karaktär och trenden går alltmer mot fokuserade fabriker. Det innebär att ett fåtal fabriker som var och en fokuserar på ett fåtal produkter tar hand om produktionen för hela världsmarknaden. Då tillverkningen sker på få utvalda platser och marknader världen över ska försörjas ifrån dessa krävs ett globalt distributionssystem som ska klara av att hantera den ökade konkurrensen, kundernas krav på kortare ledtider och den ökade differentieringen av produkter.

    Det finns olika strategier för att hantera ett globalt distributionssystem. Syftet med denna uppsats är att utreda om en transitlagerstrategi kan vara ett konkurrenskraftigt komplement eller alternativ till de mer vanligt förekommande distributionsstrategierna. Studien har gjorts genom att skapa ett teoretiskt ramverk vilket beskriver hur det globala distributionssysteme kan hanteras. Med förutsättningen att företagen idag har ett globalt distributionssystem måste de kunna distribuera sina varor över hela världen och teorin behandlar tre distributionsstrategier för att hantera detta och det är centraliserad distributionsstrategi, decentraliserad distributionsstrategi och transitlagerstrategi. De olika distributionsstrategiernas egenskaper samt för- och nackdelar beskrivs för att avgöra i vilka affärsmiljöer respektive strategi lämpar sig.

    Det teoretiska ramverket behandlar hur företag kan välja mellan och kombinera de olika distributionsstrategierna utifrån deras förutsättningar att produkterna ska nå många marknader från ett fåtal fabriker. För att underlätta valet av distributionsstrategi har en matris konstruerats i ramverket. Matrisen bygger på ett antal utvalda variabler vilka är viktiga att ta hänsyn till. Avslutningsvis när en strategi eller en kombination av strategier är vald ska teorin behandla hur företagen praktiskt kan arbeta med de olika strategierna.

    Empirin kommer att redogöra för två fallstudier där de olika företagen är Etylenaminer och Eka Chemicals. Det kommer att beskrivas hur deras distributionssystem ser ut idag, vilka distributionsstrategier som de använder samt hur de arbetar praktiskt med dem.

    I analysen har det teoretiska ramverket ställts emot den insamlade empirin för att utreda om transitlagerstrategin kan vara ett konkurrenskraftigt komplement till den centrala distributionsstrategin och den decentraliserade distributionsstrategin. Den slutsats som forskningen leder fram till är att det finns mer än ett sätt att strukturera distributionssystemet på och genom det bli framgångsrik på en global marknad. Oavsett vilket distributionssystem ett företag har byggt upp kan transitlagerstrategin utgöra ett bra komplement eller alternativ till den centraliserade distributionsstrategin och den decentraliserade distributionsstrategin för att vinna konkurrensfördelar på marknaderna. Transitlagerstrategin kan bland annat ge upphov till kortare ledtider än vad som kan uppnås med den centraliserade distributionsstrategin och mindre kapitalbindning än vad tillämpningen av den decentraliserade distributionsstrategin ger genom att produkten inte behöver lagras lokalt för att erbjuda kunden korta ledtider. Forskningen visar vidare på att det tar mycket lång tid att utveckla en renodlad transitlagerstrategi men att företagen redan i de tidiga utvecklingsfaserna av strategin kan tillgodogöra sig stora konkurrensfördelar.

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