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  • 51.
    Barlas, Sofia
    et al.
    University of Skövde, School of Engineering Science.
    Buerba, Adriana
    University of Skövde, School of Engineering Science.
    Analyze, consolidate and improve the product development process at Parker Hannifin QCDE through implementation of DFMA principles2017Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Parker Hannifin QCDE aim to eliminate as much wasted time, materials and resources as achievable by implementing Design for Manufacturing and Assembly principles into a modified version of their Product Development Process. The modified Product Development Process was developed within this project with the objective of aiding the company to remain competitive within their field, as well as continue to efficiently develop and produce high quality products.

     

    A literature study was performed to gain a greater understanding of the multiple Design for Excellence methods and their possibilities to enhance the Product Development Process at Parker Hannifin QCDE. The literature study included various sources such as academic books and scientific articles.

     

    An empirical study was conducted and the use of the current Internal Product Development Process was evaluated in conjunction with a detailed evaluation of the designated coupling. An additional aspect that was explored includes an evaluation of the extent of Design for Manufacturing and Assembly that is implemented into the current Internal Product Development Process.

     

    The Generation chapter of this thesis outlines the sequence and process implemented for generating the modified Internal Product Development Process and implementing Design for Manufacturing and Assembly. The results of this thesis project included implementing Design for Manufacturing and Assembly in the form of checklists. The multiple Design for Excellence checklists were inspired in part by the information obtained from the literature study and the authors interpretation. The finished concept has been provided to Parker Hannifin QCDE in the form of a pamphlet including instructions of how to implement the checklists into the modified Internal Product development process.

     

    The discussion chapter within this report consists of a conclusion and deliberation regarding the methodology used within this thesis. The results obtained from this thesis have been dissected and evaluated along with implications and potential weaknesses in the work.

  • 52.
    Barrera Diaz, Carlos Alberto
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Oscarsson, Jan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Lidberg, Simon
    Volvo Car Corporation, Skövde, Sweden.
    Sellgren, Tommy
    Volvo Car Corporation, Skövde, Sweden.
    A Study of Discrete Event Simulation Project Data and Provenance Information Management in an Automotive Manufacturing Plant2017In: Proceedings of the 2017 Winter Simulation Conference / [ed] W. K. V. Chan, A. D’Ambrogio, G. Zacharewicz, N. Mustafee, G. Wainer, E. Page, IEEE, 2017, , p. 12p. 4012-4023Conference paper (Refereed)
    Abstract [en]

    Discrete Event Simulation (DES) project data management is a complex and important engineering activity which impacts on an organization’s efficiency. This efficiency could be decreased by the lack of provenance information or the unreliability of existing information regarding previous simulation projects, all of which complicates the reusability of the existing data. This study presents an analysis of the management of simulation projects and their provenance data, according to the different types of scenarios usually found at a manufacturing plant. A survey based on simulation projects at an automotive manufacturing plant was conducted, in order to categorize the information regarding the studied projects, map the available provenance data and standardize its management. This study also introduces an approach that demonstrates how a structured framework based on the specific data involved in the different types of scenarios could allow an improvement of the management of DES projects.

  • 53.
    Beheshtinia, Mohammad Ali
    et al.
    Department of Industrial Engineering, University of Semnan, Iran.
    Ahmadi, Bahar
    Department of Industrial Engineering, University of Semnan, Iran.
    Fathi, Masood
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    A Genetic Algorithm with Multiple Populations to Reduce Fuel Consumption in Supply Chain2019In: International Journal of Transportation Engineering, ISSN 2322-259XArticle in journal (Refereed)
    Abstract [en]

    Reducing fuel consumption by transportation fleet in a supply chain, reduces transportation costs and consequently, the product final cost. Moreover, it reduces environmental pollution, and in some cases, it helps governments constitute less subsidies for fuels. In this paper, a supply chain scheduling is studied, with the two objective functions of minimizing the total fuel consumption, and the total order delivery time. After presenting the mathematical model of the problem, a genetic algorithm, named Social Genetic Algorithm (SGA) is proposed to solve it. The proposed algorithm helps decision makers determine the allocation of orders to the suppliers and vehicles and production and transportation scheduling to minimize total order delivery time and fuel consumption. In order for SGA performance evaluation, its results are compared with another genetic algorithm in the literature and optimal solution. Finally, a sensitivity analysis is performed on SGA. The results of comparisons also show the high performance of SGA. Moreover, by increasing the number of suppliers and vehicles and decreasing the number of orders, the value of the objective function is reduced.

  • 54.
    Beijer, Anton
    et al.
    University of Skövde, School of Technology and Society.
    Lindholm, Magnus
    University of Skövde, School of Technology and Society.
    Beräkning av pumpkapacitet samt konstruktion av pumpfundament2013Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    A development project to solve problems with why submersible pumps in a run-off system broke down with periods of two years, on average, was performed in collaboration with Cementa AB in Skövde. Reason for the pumps breakdowns was searched and found to be inadequate procedures and missing knowledge of the maintenance required on the pumps. To solve this problem, guidelines for the purchase of new dry pit pumps were developed to allow for continuous maintenance. As the possibilities of placing a dry well pump did not exist at Cementa, a pump foundation was developed.

    Requirements for the development work were produced in cooperation with Cementas maintenance department and theoretical dimensioning of the submersible bilge pumps volume flow capacity was performed. Requirements were evaluated and weighted using Pairwise comparison. The design and control of the strength of the developed pump foundation was performed using finite element analysis in the software Pro/Engineer Creo 1.0 Mechanica. Controls of the strength of the attachment of the pump foundation and welds were performed analytically.

    The work resulted in a recommendation to Cementa AB in Skövde to bring in quotes on the new dry-pit pumps using the developed guidelines and to manufacture the pump foundation developed within the framework of the thesis. Cementa was also recommended to carefully follow the maintenance instructions for pumps and make it easier for staff to perform this maintenance. This was recommended to ensure that new pumps would have a longer and more economical lifetime.

  • 55.
    Bergh, Eric
    et al.
    University of Skövde, School of Engineering Science.
    Niklasson, Ludwig
    University of Skövde, School of Engineering Science.
    Konstruktion av förvaringsenhet för transport av bearbetningsverktyg2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Brodit is a manufacturing industry that develops equipment for mobile units in which the design, processing, assembly and sale of products occur. In order to optimize the processing process, Brodit wants to introduce automated systems that standardize handling, transport and installation of CNC tools.

    The main objective of the project was defined to produce a proposal for a standardized storage and transport solution. The results are presented using a CAD model that visualizes the final concept and its substructures. Frequency and strength analyzes have been performed with the finite element method to ensure quality and minimize risks with the design. Discussion on remaining uncertainties regarding automation aspects, alternative solutions and other surrounding factors was conducted. As a conclusion, the initial goals set for the project are compared with the results achieved. Proposals for future development areas and continued work were listed.

  • 56.
    Berglund, Sofie
    University of Skövde, School of Technology and Society.
    Kostnadseffektiv design och framtagning av flexibel innerförpackning åt elektronikprodukter2013Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Abilia develops, manufactures and sells aids for people who have either a physical or mental limitations that affect their everyday lives. In order to save money and get a better uniformity Abilia want to standardize the packaging and develop a flexible interior that can be adapted to many of the company’s products.

    A pilot study laid the foundation for the project where many different areas and methods were examined. The existing packages were evaluated, and their and the products lifecycles were identified and that made it clear who the projects user was. They were interviewed and a product specification could be established. The pilot study resulted that it was two groups of products and the solution must be able to adapt to both. The solution must also be flexible to the products and their accessories. The Hjälpmedelscentralerna turned out to be the users in this project and they had requirements that the solution must be sustainable and provide a more structured inside of the packaging.

    Concepts were generated with a practical idea generation that resulted in different forms and constructions. The concept selection was made after discussion with the staff from Abilia and through a balanced concept selection matrix. The project resulted in a flexible and durable interior in two parts. A product presentation part which has a design with folddown flaps that allows the product to get stuck no matter which size and a flexible accessory which can be adjusted both vertically and horizontally. The solution fulfills the requirements from the product specification and has been verified by expert that it would work in real situation. The material in the solution is the best suited for the function and it is also the material with the lowest environmental impact of those surveyed in the project.

  • 57.
    Bergman, Christian
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Bäckstrand, Gunnar
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Swerea IVF AB, Gothernburg, Sweden.
    Moestam, Lena
    Volvo Group Trucks Operations, Gothenburg, Sweden.
    A Library Based Tool to Assist the Generative Activity in Workstation Design2014In: Advances in Ergonomics in Design, Usability & Special Populations: Part II / [ed] Francisco Rebelo and Marcelo Soares, AHFE Conference , 2014, p. 206-214Conference paper (Refereed)
  • 58.
    Bergman, Emil
    et al.
    University of Skövde, School of Engineering Science.
    Wikström, Anna
    University of Skövde, School of Engineering Science.
    Påkörningsskydd i bearbetningsfabriker: Utveckling av påkörningsskydd för industrifordon2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In a large part of the industrial accidents different kinds of forklifts are involved. Collision protection barriers are often used to prevent pedestrians from coming into direct contact with industrial vehicles. The Volvo Group Truck Operations facility in Skövde uses such collision protection barriers to separate pedestrians from industrial traffic. Volvo’s welded steel collision protection barriers are constructed in place, depending on need, and are fastened to the concrete floor with expander bolts. The barriers are, therefore, difficult to disassemble and reuse in other locations. Volvo has requested the development of a conceptual design of a reusable and repairable modular collision protection barrier. To ensure that the specifications for the product are fulfilled strength calculations are performed.

    In order to complete the work a literature survey is carried out where current collision protection barriers, fastening methods for concrete, methods of calculations, safety demands and a product developing process are examined. Interviews are conducted and on-site observations are made to identify the necessary specifications. Observations showed that in a collision the expander bolts often tear loose from the concrete floor due to the robustness of the current collision barriers. The specifications are used to generate concepts. The developed concepts are evaluated and evolved in an iterative process where the specifications are refined at each step. The result, a modular conceptual design with two different alternatives to fasten it to the concrete floor, is presented. The idea is that the conceptual design shall be sized to give way at the maximum load of the fastening alternative.

    Strength calculations, performed on the most critical components, shows that it is difficult to size the collision protection barrier to guarantee that the intended component breaks in a collision. A Failure Mode and Effects Analysis is conducted to identify any flaws in the conceptual design and suggestions to address the flaws are made.

    The conceptual design fulfils the specifications that are currently possible to evaluate. These specifications are that the design is modular, easy to disassemble, repair and reuse, easy to store and meets the safety demands.

    Further work with strength calculations and sizing of the collision protection barrier is required. To ensure that the specifications are fulfilled and that the collision protection barrier behaves as desired in a collision it is recommended that prototypes be manufactured and tested. 

  • 59.
    Bergqvist, Ellen
    et al.
    University of Skövde, School of Technology and Society.
    Forsander, Leif
    University of Skövde, School of Technology and Society.
    Framtagande och införande av process för metodisk produktutveckling: specifikt för Tibrokök2012Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med examensarbetet är att hjälpa Tibrokök med produktutveckling, Tibrokök har idag en enkel processplan vid produktutveckling som inte används fullt ut eller som det var tänkt, därför utformas en ny produkt-utvecklingsprocess specifik för Tibrokök. Under förstudien i examensarbetet upptäcks flera brister inom produktutveckling på Tibrokök exempelvis onödig väntan på beslut och oklara regler eller roller, målet är att reducera dessa brister så att produktutveckling på företaget kan bedrivas effektivare.

    Observationer, existerande hjälpmedel och personalens erfarenheter inom produktutveckling på Tibrokök tas tillvara vid framtagningen av den nya produktutvecklingsprocessen.

    För att underlätta införandet av det nya arbetssättet för produktutveckling ut-formas en produktutvecklingsguide som är ett hjälpmedel till produktutveck-lingsprocessen. Produktutvecklingsguiden ska även stärka kommunikationen och dokumentationen inom produktutveckling på Tibrokök. Dokumentationen stärks genom ett antal underlag som tas fram tillhörande produktutvecklings-processen.

    Produktutvecklingsprocessens funktionalitet testas och utvärderas genom simulering av två produktutvecklingsprojekt, simuleringarna säkerställer om produktutvecklingsprocessen är tillräckligt generell för att passa alla typer av produktutvecklingsprojekt.

    Resultatet blir en produktutvecklingsprocess speciellt anpassad för Tibrokök. Med hjälp av den framtagna produktutvecklingsguiden kan all personal oavsett förkunskap använda produktutvecklingsprocessen.

    För att implementera det nya arbetssättet med produktutveckling på Tibrokök utförs utbildande redovisningar och en workshop med personalen. Som ett slutligt steg överlämnas ett antal rekommendationer om ändringar i Tibroköks arbetssätt för att utföra effektivare produktutveckling.

  • 60.
    Bergstedt, Pontus
    et al.
    University of Skövde, School of Engineering Science.
    Svemark, Viktor
    University of Skövde, School of Engineering Science.
    Konstruktion av stegmatare för vevstakar2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This work describes the preparatory work and construction of a step feeder that sorts and orients connecting rods in a cycle time of ten seconds. Industries are often dependent of different material handling operations which assures a specific material orientation, which validates the importance of this work. This has been done by dividing the machine into two main functions; Stair case-function, which pre-sorts and transports the connecting rods further to the second function, the orientation- function where the orientation is performed.

    By using methods such as; design for manufacture & assembly, failure mode & effects analysis and softwares for material database handling, computer aided design and numerical strength analysis a construction could be formulated which reflects the aspects that characterize a well-planned product. Seven different design-methods were used in order to generate and evaluate ideas in several iterated steps. Ten investigative experiments were conducted as an additional evaluation of concepts and as a basis for further calculations and conclusions.

    The formulation of the step feeder resulted in a single-acting stair with two moving stairs and a static between them for transfer. A single-feeder after the staircase in the shape of a “paddle wheel” ensures that the connection rods are delivered one-by-one to the orientation-function while also ensuring the cycle time. An orientation-function consisting of a “conveyor“ that with the aid of friction and an offset of the center of gravity orients the connecting rods with the crankshaft-end first. Lastly were three critical areas in the construction further examined with finite element method with passing results.

    All objectives for the project were achieved, the step feeder have for instance fewer unique components than existing solutions. The ambition was to design the step feeder with a low grade of complexity and without sensors have permeated throughout the entire project, which also was achieved.

  • 61.
    Bergström, Bjarne
    et al.
    University of Skövde, School of Technology and Society.
    Sellgren, Tommy
    University of Skövde, School of Technology and Society.
    Flödessimulering och simuleringsbaserad optimering för bristidentifiering och förbättring av bearbetningslinje: Genom data-analys, modellering och flermålsoptimering2013Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
  • 62.
    Bergström, Martina
    et al.
    University of Skövde, School of Technology and Society.
    Larsson, Ida
    University of Skövde, School of Technology and Society.
    Kommunikation i kundorderprocessen: En fallstudie på OFFECCT2007Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis emphasizes the importance of efficient communication on an internal and external level as well as how an organisation should use communication in order to improve its business. Logistics is considered to be a tool for controlling different flows and it can be used to fulfil the needs and wishes of a customer. This thesis has been carried out at the furniture company OFFECCT that cooperates with internationally known designers to develop furniture for a private and public environment. A previous mapping of the orderfulfilment process at this company proved that the communication is not satisfactory. It is very important for OFFECCT as a rather small company to pull off an efficient communication on an internal and external level in order to survive on the market. Some of the reasons for focusing on communication are an increased return on investment and an improved customer service.

    The orderfulfilment process includes several activities, starting off with a need and is finished by the distribution of products and after sales service. The activities create a flow with different kinds of information that are to be sent in between the persons in charge of each activity. The kind of information can vary depending on where in the flow it is located. In order to communicate this information, a process to transmit the message is required so that an interpretation of the sent message is possible. By using different sorts of communication channels, a company can send certain information in a specific way to enhance the scattering of information. Communication and information can be either formal or informal depending on whether it is work related or not. Furthermore, communication should be carried out internal within the company and external with interested parties to obtain a solid organisation that changes with its surroundings. How well a company communicates information can be determined by a few factors such as actual distances and organisational structures.

    Observations and interviews at OFFECCT revealed a few problems within the communication aspects that cause an inferior customer service and difficulties to carry out the orderfulfilment process efficiently. An analysis of the empirical information resulted in a few ideas for improvements and a general process that can be used to improve communication, which are presented further in the thesis.

  • 63.
    Bernedixen, Jacob
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Automated Bottleneck Analysis of Production Systems: Increasing the applicability of simulation-based multi-objective optimization for bottleneck analysis within industry2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Manufacturing companies constantly need to explore new management strategies and new methods to increase the efficiency of their production systems and retain their competitiveness. It is of paramount importance to develop new bottleneck analysis methods that can identify the factors that impede the overall performance of their productionsystems so that the optimal improvement actions can be performed. Many of the bottleneck-related research methods developed in the last two decades are aimed mainly at detecting bottlenecks. Due to their sole reliance on historical data and lackof any predictive capability, they are less useful for evaluating the effect of bottleneck improvements.

    There is an urgent need for an efficient and accurate method of pinpointing bottlenecks, identifying the correct improvement actions and the order in which these should be carried out, and evaluating their effects on the overall system performance. SCORE (simulation-based constraint removal) is a novel method that uses simulation based multi-objective optimization to analyze bottlenecks. By innovatively formulating bottleneck analysis as a multi-objective optimization problem and using simulation to evaluate the effects of various combinations of improvements, all attainable, maximum throughput levels of the production system can be sought through a single optimization run. Additionally, post-optimality frequency analysis of the Pareto-optimal solutions can generate a rank order of the attributes of the resources required to achieve the target throughput levels. However, in its original compilation, SCORE has a very high computational cost, especially when the simulation model is complex with a large number of decision variables. Some tedious manual setup of the simulation based optimization is also needed, which restricts its applicability within industry, despite its huge potential. Furthermore, the accuracy of SCORE in terms of convergence in optimization theory and correctness of identifying the optimal improvement actions has not been evaluated scientifically.

    Building on previous SCORE research, the aim of this work is to develop an effective method of automated, accurate bottleneck identification and improvement analysis that can be applied in industry.

    The contributions of this thesis work include:

    (1) implementation of a versatile representation in terms of multiple-choice set variables and a corresponding constraint repair strategy into evolutionary multi-objective optimization algorithms;

    (2) introduction of a novel technique that combines variable screening enabled initializationof population and variable-wise genetic operators to support a more efficient search process;

    (3) development of an automated setup for SCORE to avoid the tedious manual creation of optimization variables and objectives;

    (4) the use of ranking distance metrics to quantify and visualize the convergence and accuracy of the bottleneck ranking generated by SCORE.

    All these contributions have been demonstrated and evaluated through extensive experiments on scalable benchmark simulation models as well as several large-scale simulation models for real-world improvement projects in the automotive industry.

    The promising results have proved that, when augmented with the techniques proposed in this thesis, the SCORE method can offer real benefits to manufacturing companies by optimizing their production systems.

  • 64.
    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, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Multiple Choice Sets and Manhattan Distance Based Equality Constraint Handling for Production Systems OptimizationIn: Computers & Operations Research, ISSN 0305-0548, E-ISSN 1873-765XArticle in journal (Refereed)
    Abstract [en]

    Many simulation-based optimization packages provide powerful algorithms to solve industrialproblems. But most of them fail to oer their users the techniques they needto eectively handle multiple-choice problems involving a large set of decision variableswith mixed types (continuous, discrete and combinatorial) and problems that are highlyconstrained (e.g., with many equality constraints). Yet such issues are found in manyreal-world production system design and improvement problems. Thus, this paper introducesa method to eectively embed multiple choice sets and Manhattan-distancebasedconstraint handling into multi-objective optimization algorithms like NSGA-II andNSGA-III. This paper illustrates and evaluates how these two techniques have been appliedtogether to solve optimal workload, buer and workforce allocation problems. Anexample follows, showing their application to a complex production system improvementproblem at an automotive manufacturer.

  • 65.
    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, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Practical Production Systems Optimization Using Multiple-Choice Sets and Manhattan Distance based Constraints Handling2014In: Industrial Simulation Conference, Skövde, June 11-13, 2014, 2014, p. 97-103Conference paper (Refereed)
    Abstract [en]

    Many simulation-based optimization packages provide powerful algorithms to solve large-scale system problems. But most of them fall short to offer their users the techniques to effectively handle decision variables that are of multiple-choice type, as well as equality constraints, which can be found in many real-world industrial system design and improvement problems. Hence, this paper introduces how multiple choice sets and Manhattan-distance-based constraint handling can be effectively embedded into a meta-heuristic algorithm for simulation-based optimization. How these two techniques have been applied together to make the improvement of a complex production system, provided by an automotive manufacturer, possible will also be presented.

  • 66.
    Bernedixen, Jacob
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    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.
    On the convergence of stochastic simulation-based multi-objective optimization for bottleneck identificationIn: International Journal of Production Research, ISSN 0020-7543, E-ISSN 1366-588XArticle in journal (Refereed)
    Abstract [en]

    By innovatively formulating a bottleneck identication problem into a bi-objective optimization,simulation-based multi-objective optimization (SMO) can be eectively used as a new method for gen-eral production systems improvement. In a single optimization run, all attainable, maximum throughputlevels of the system can be sought through various optimal combinations of improvement changes ofthe resources. Additionally, the post-optimality frequency analysis on the Pareto-optimal solutions cangenerate a rank order of the attributes of the resources required to achieve the target throughput levels.Observing that existing research mainly put emphasis on measuring the convergence of the optimizationin the objective space, leaving no information on when the solutions in the decision space have convergedand stabilized, this paper represents the rst eort in increasing the knowledge about the convergence ofSMO for the rank ordering in the context of bottleneck analysis. By customizing the Spearman's footruledistance and Kendall's tau, this paper presents how these metrics can be used eectively to provide thedesired visual aid in determining the convergence of bottleneck ranking, hence can assist the user todetermine correctly the terminating condition of the optimization process. It illustrates and evaluatesthe convergence of the SMO for bottleneck analysis on a set of scalable benchmark models as well as twoindustrial simulation models. The results have shed promising direction of applying these new metrics tocomplex, real-world applications.

  • 67.
    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, 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.
    Variables Screening Enabled Multi-Objective Optimization for Bottleneck Analysis of Production SystemsManuscript (preprint) (Other academic)
    Abstract [en]

    Bottleneck analysis can be defined as the process that includes both bottleneck identification and improvement. In the literature most of the proposed bottleneck-related methods address mainly bottleneck detection. By innovatively formulating a bottleneck analysis into a bi-objective optimization method, recent research has shown that all attainable, maximized TH of a production system, through various combinations of improvement changes of the resources, can be sought in a single optimization run. Nevertheless, when applied to simulation-based evaluation, such a bi-objective optimization is computationally expensive especially when the simulation model is complex and/or with a large amount of decision variables representing the improvement actions. The aim of this paper is therefore to introduce a novel variables screening enabled bi-objective optimization that is customized for bottleneck analysis of production systems. By using the Sequential Bifurcation screening technique which is particularly suitable for large-scale simulation models, fewer simulation runs are required to find the most influenacing factors in a simulation model. With the knowledge of these input variables, the bi-objective optimization used in the bottleneck analysis can customize the genetic operators on these variables individually according to their rank of main effects with the target to speed up the entire optimization process. The screening-enabled algorithm is then applied to a set of experiments designed to evaluate how well it performs when the number of variables increases is a scalable, benchmark model, as well as two real-world industrial-scale simulation models found in the automotive industry. The results have illustrated the promising direction of incorporating the knowledge of influencing variables and variable-wise genetic operators into a multi-objective optimization algorithm for bottleneck analysis.

  • 68.
    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.

  • 69.
    Bertilsson, Erik
    et al.
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    Chalmers University of Technology.
    Using experimental design to define boundary manikins2012In: Work: A Journal of Prevention, Assessment and Rehabilitation, ISSN 1051-9815, Vol. 41, p. 4598-4605Article in journal (Refereed)
    Abstract [en]

    When evaluating human-machine interaction it is central to consider anthropometric diversity to ensure intended accommodation levels. A well-known method is the use of boundary cases where manikins with extreme but likely measurement combinations are derived by mathematical treatment of anthropometric data. The supposition by that method is that the use of these manikins will facilitate accommodation of the expected part of the total, less extreme, population. In literature sources there are differences in how many and in what way these manikins should be defined. A similar field to the boundary case method is the use of experimental design in where relationships between affecting factors of a process is studied by a systematic approach. This paper examines the possibilities to adopt methodology used in experimental design to define a group of manikins. Different experimental designs were adopted to be used together with a confidence region and its axes. The result from the study shows that it is possible to adapt the methodology of experimental design when creating groups of manikins. The size of these groups of manikins depends heavily on the number of key measurements but also on the type of chosen experimental design.

  • 70.
    Bertilsson, Erik
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Keyvani, Ali
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden / Innovatum AB, Trollhättan, Sweden.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Hanson, Lars
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Assessment of manikin motions in IMMA2012In: Advances in Applied Human Modeling and Simulation / [ed] Vincent G. Duffy, Boca Raton: CRC Press, 2012, p. 235-244Chapter in book (Refereed)
    Abstract [en]

    When evaluating human-machine interaction in a virtual environment using Digital human modelling (DHM) it is important to ensure that the predicted motions lie within the range of behavioural diversity for different people within a population. This paper presents a study in which a comparison is made between motions predicted by the DHM tool IMMA (Intelligently Moving Manikin) and motions from real humans stored in a motion database. Results show similar motions but the predicted motions were in total statistically significantly different compared to the motions performed by real persons. The differences are most likely due to the balance function and joint constraints that the IMMA tool uses for predicting motions. Differences can also be due to other factors, aside of body size, such as age, gender or strength that affects the movement behaviour.

  • 71.
    Bi, Z. M.
    et al.
    Department of Engineering, Indiana University Purdue University Fort Wayne, Fort Wayne, IN, USA.
    Wang, Lihui
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Optimization of machining processes from the perspective of energy consumption: A case study2012In: Journal of manufacturing systems, ISSN 0278-6125, E-ISSN 1878-6642, Vol. 31, no 4, p. 420-428Article in journal (Refereed)
    Abstract [en]

    One of the primary objectives of sustainable manufacturing is to minimize energy consumption in its manufacturing processes. A strategy of energy saving is to adapt new materials or new processes; but its implementation requires radical changes of the manufacturing system and usually a heavy initial investment. The other strategy is to optimize existing manufacturing processes from the perspective of energy saving. However, an explicit relational model between machining parameters and energy cost is required; while most of the works in this field treat the manufacturing processes as black or gray boxes. In this paper, analytical energy modeling for the explicit relations of machining parameters and energy consumption is investigated, and the modeling method is based on the kinematic and dynamic behaviors of chosen machine tools. The developed model is applied to optimize the  machine setup for energy saving. A new parallel kinematic machine Exechon is used to demonstrate the procedure of energy modeling. The simulation results indicate that the optimization can result in 67% energy saving for the specific drilling operation of the given machine tool. This approach can be extended and applied to other machines to establish their energy models for sustainable manufacturing.

  • 72.
    Bi, Z.M.
    et al.
    Queen's University Belfast.
    Wang, Lihui
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Design of a Cobot with Three Omni-Wheels2009In: Proceedings of the 19th International Conference on Flexible Automation and Intelligent Manufacturing, FAIM 2009 , 2009, p. 186-193Conference paper (Refereed)
    Abstract [en]

    Collaborative robots (Cobots) have been proposed to guide and assist human operators to move heavy objects in a given trajectory. Most of the existing cobots us steering wheels; typical drawbacks of using steering wheels include (i) the difficulty to follow a trajectory with a curvature larger than that of the base platform, (ii) the difficulty to mount encoders on steering wheels due to self-spinning of the wheels, and (iii) the difficulty to quarantine dynamic control performance since it is purely kinematic control. In this paper, a new cobot with the omni-wheels has been proposed, and its design model has been developed, and a simulation has been conducted to validate this control performance.

  • 73.
    Biel, Anders
    University of Skövde, School of Technology and Society.
    Constitutive behaviour and fracture toughness of an adhesive layer2005Licentiate thesis, monograph (Other scientific)
    Abstract [en]

    This report presents the fracture energy and the complete stress – elongation relation for a structural adhesive loaded in modus I. The experiments are performed on the Double Cantilever Beam (DCB) specimen and the method to analyse the experiments is based on the J-integral approach which means that the energy release rate, i.e. J, is measured continuously during an experiment. Since J is given by the area under the stress – elongation relation for the adhesive layer, both the fracture energy and the stress – elongation relation can be measured in the experiments. The geometry of the specimens is varied in order to examine if the evaluated stress – elongation relation is a unique constitutive relation for the adhesive layer. No dependence on the specimen geometry has been detected provided that the adherends only deform elastically. If the adherends are allowed to deform plastically the fracture energy increases and the stress – elongation relation from the elastically deforming tests cannot be used to simulate the structural behaviour. This is interpreted as an effect of a substantially shorter damage zone with the plastically deforming adherends. An evaluation of effects of the loading rate is also performed. This shows that the fracture energy increases with the loading rate. A number of standardized methods are available to evaluate the fracture properties of adhesives from experiments on the DCB-specimen. Furthermore, alternative methods have recently been suggested by Tamuzs et al. (2003). In an effort to examine the accuracy of the alternative methods, FE-simulations are performed and evaluated according to the alternative methods. The simulations are based on the stress – elongation relation evaluated from the present experiments. Large differences between the correct and the evaluated fracture energies are found for most of the methods. Two of the methods show good accuracy and appear particularly promising. Stress whitening is used to evaluate the length of the damage zone. This length compares reasonably well with the length evaluated from FE-simulations of the experiments.

  • 74.
    Biel, Anders
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Alfredsson, K. Svante
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Carlberger, Thomas
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Adhesive Tapes; Cohesive Laws for a Soft Layer2014In: Procedia Materials Science, ISSN 2211-8128, Vol. 3, p. 1389-1393Article in journal (Refereed)
    Abstract [en]

    For adhesive tapes, the strain before fracture often exceeds 500%. Although the maximum stresses are quite modest the high strains to fracture result in impressive fracture energy. Due to hydrostatic stress the fracture process often starts by nucleation of microscopic cracks inside the layer. The final crack path is usually close to one of the adherends.

    Repeated experiments are performed both with DCB-specimens and butt-joints. The used adhesive tape is an acrylic foam tape with a thickness of 1.1 mm and a width of 19 mm. The geometry of the specimen is adapted to the properties of the soft layer. For the DCB-specimen this implies that the length of the specimen is about 1 m. The evaluated cohesive laws from the DCB- specimens give a fracture energy of 2 kN/m and a maximum stress about 0.5 MPa. For the butt-joints, the evaluated cohesive law corresponds well to the results from the DCB-experiments. However, the strain to fracture is slightly smaller. The stress in these specimens is distributed over a larger area and a nucleated crack rapidly crosses the load bearing area and fails the joint prematurely. For both kinds of experiments the evaluated cohesive laws show a small linear part. After this part there is an almost linear strain-hardening phase until fracture.

  • 75.
    Biel, Anders
    et al.
    Department of Wind Energy, Technical University of Denmark, Roskilde, Denmark.
    Stigh, Ulf
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Cohesive zone modelling of nucleation, growth and coalesce of cavities2017In: International Journal of Fracture, ISSN 0376-9429, E-ISSN 1573-2673, Vol. 204, no 2, p. 159-174Article in journal (Refereed)
    Abstract [en]

    The stress-deformation relation i.e. cohesive law representing the fracture process in an almost incompressible adhesive tape is measured using the double cantilever beam specimen. As in many ductile materials, the fracture process of the tape involves nucleation, growth and coalesce of cavities. This process is studied carefully by exploiting the transparency of the used materials and the inherent stability of the specimen configuration. Utilising the path independence of the J -integral, the cohesive law is measured. The law is compared to the results of butt-joint tests. The law contains two stress peaks—the first is associated with nucleation of cavities at a stress level conforming to predictions of void nucleation in rubber elasticity. The second stress peak is associated with fracture of stretched walls between fully-grown cavities. After this second peak, a macroscopic crack is formed. The tape suffers at this stage an engineering strain of about 800%. A numerical analysis with the determined cohesive law recreates the global specimen behaviour.

  • 76.
    Biel, Anders
    et al.
    Karlstad University.
    Stigh, Ulf
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Comparison of J-integral methods to experimentally determine cohesive laws in shear for adhesives2019In: International Journal of Adhesion and Adhesives, ISSN 0143-7496, E-ISSN 1879-0127, Vol. 94, p. 64-75Article in journal (Refereed)
    Abstract [en]

    High-quality simulation methods demand accurate material models. In simulations an adhesive can be represented by a cohesive layer. A cohesive layer model utilizes a cohesive law to represent the homogenized mechanical behaviour of a layer with a thickness. In the current paper we use three experimental methods to measure the cohesive law in shear using the ENF-specimen; one of the methods is novel and is also useful for evaluation of experiments with the ELS-specimen. Two sets of experiments are performed, one with elastic substrates and one with plastically deforming substrates. Each experiment is evaluated using all three methods. The evaluation shows that all methods provide reasonable data; the results are similar if the substrates are elastic. With smaller specimens, the substrates deform plastically and one of the methods is identified as the most accurate.

  • 77.
    Biel, Anders
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Stigh, Ulf
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Strength and toughness in shear of constrained layers2018In: International Journal of Solids and Structures, ISSN 0020-7683, E-ISSN 1879-2146, Vol. 138, p. 50-63Article in journal (Refereed)
    Abstract [en]

    Confined layers may fracture in shear. This occurs, for example in adhesive joints and composite materials. A common mechanism for shear fracture is the formation of shear hackles associated with an expansion of the layer. This makes shear toughness and strength depend on the constraint of the expansion. By constraining the expansion using external loading in experiments, the expansion is reduced but not totally inhibited. The experiments are evaluated using the path independent properties of the J-integral. It is shown that the shear toughness increases for the more constrained case. Thus, from a strength analysis perspective, ignoring the expansion leads to a conservative estimate of the fracture properties. Extrapolation of the evaluated properties to totally inhibited expansions gives the traction separation relation and the fracture toughness for a layer in simple shear.

  • 78.
    Biel, Anders
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Stigh, Ulf
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Walander, Tomas
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Life Sciences.
    A Critical Study of an Alternative Method to Measure Cohesive Properties of Adhesive Layers2012In: Proceedings of the 19th European Conference on Fracture, Kazan Scientific Centre of the Russian Academy of Sciences , 2012Conference paper (Refereed)
    Abstract [en]

    A perfect experiment is only sensitive to the properties to be analysed. However, evaluation of experimental results is always based on assumptions. Depending on the assumptions, the derived results are more or less correct. In this paper a method based on linear elastic fracture mechanics is compared to a method based on the path independence of the J-integral and the assumptions of the existence of a cohesive zone. Contrary to the other methods, the J-integral method only rests on the assumption that the material of the specimen has a strain energy density that not explicitly depends on the position in the direction of crack propagation. That is, the conditions for J to be path independent. Evaluation of simulated experiments gives the exact value of the fracture energy. The alternative method is based on linear elastic fracture mechanics. Contrary to the conventional methods we use an expression where the crack length is eliminated in favour of the flexibility of the specimen.

    Influences of assumptions are studied both experimentally and numerically. Differences in stiffness are achieved by changing the type of adhesive and the layer thickness. Two different adhesives are studied. One is a modern crash resistant epoxy adhesive, SikaPower-498. This is a relatively stiff and tough adhesive. The other adhesive is a soft and extremely tough polyurethane based adhesive, Sikaflex-UHM. Two layer thicknesses are tested; 1.0 mm for the epoxy and 3.0 mm for the polyurethane based adhesive. The results show that the two methods give similar results for the thinner and stiffer epoxy adhesive but differences are recorded for the soft polyurethane based adhesive. This analysis gives a better understanding of the evaluation methods and their limitations and possibilities to extract cohesive laws.

  • 79.
    Blomé, Mikael
    et al.
    Lunds Universitet.
    Dukic, Tania
    Chalmers.
    Hanson, Lars
    Lunds Universitet.
    Högberg, Dan
    University of Skövde, School of Engineering Science.
    Web-Based Protocol for Human Simulation Process and Documentation2003Conference paper (Other academic)
  • 80.
    Blåder, Philip
    University of Skövde, School of Engineering Science. philipblader@hotmail.com.
    Bestående deformation av aluminiumhus vid presspassning2018Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The deformation field of an aluminum housing that forms a press joint together with a ring wheel is analyzed in this study. The reason for the study is to get a better idea of the impact of interference fit on the aluminum housing using the Finita element method and practical measurement. Volvo Cars in Skövde asks for a method that can initially verify or dementiate deformations that may mean that the tolerances of the drawing are not obtained. The study will also provide an evaluation if the Finita element method is applicable to capture changes in the detail without confirmation of practical measurement.

    The analysis of the deformation field is performed with the Abaqus software, where the model's relevance is compared to practical measurement using a coordinate measuring machine and 3D scanner. The practical measurement is performed before and after pressing, the relevant holes and surfaces as shown. The FE model is created to mimic the dressing when the ring wheel is in place after pressing.

    The analysis shows that the material does not plasticize due to the radial displacement caused by the ring wheel. The FE simulation, on the other hand, shows that deformations occur on the relevant holes and surfaces examined during the practical measurement. Comparison between the results shows that the FE model provides a good picture of the deformation field and changes in the geometry that would mean that tolerances according to drawing would be difficult to obtain. Deviations between the results may be due to the simplifications made to the FE model but also to the measurement accuracy varied.

    FEM is considered to be applicable to create a better picture of the assembly process at an early stage before practical measurement was carried out. In order to avoid the drawing tolerances not being obtained, it is proposed that the aluminum housing be machined after pressing the ring wheel.

  • 81.
    Bohlin, R.
    et al.
    Fraunhofer-Chalmers Research Centre for Industrial Mathematics, Gothenburg, Sweden.
    Delfs, N.
    Fraunhofer-Chalmers Research Centre for Industrial Mathematics, Gothenburg, Sweden.
    Hanson, Lars
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Carlson, J. S.
    Fraunhofer-Chalmers Research Centre for Industrial Mathematics, Gothenburg, Sweden.
    Automatic creation of virtual manikin motions maximizing comfort in manual assembly processes2012In: Technologies and Systems for Assembly Quality, Productivity and Customization: Proceedings of the 4th CIRP Conference on Assembly Technologies and Systems / [ed] S. Jack Hu, Conference on Assembly Technologies & Systems (CIRP), 2012, p. 209-212Conference paper (Refereed)
    Abstract [en]

    Effective simulation of manual assembly operations considering ergonomic load and clearance demands requires detailed modeling of human body kinematics and motions, as well as a tight coupling to powerful algorithms for collision-free path planning. The focus in this paper is a unified solution that automatically creates assembly motions for manikins taking kinematic constraints, balance, contact forces, collision avoidance and comfort into account. The manikin used in this work has 162 degrees of freedom - six exterior fictitious joints determine the position of the lower lumbar and the remaining ones are interior joints. The inverse kinematic problem leads to an underdetermined system allowing us to pick a solution that maximizes a scalar valued comfort function. The comfort function offers a generic way to give preference to certain poses while avoiding others, typically by considering joint limits, forces and moments on joints, and magnitude of contact forces. In order to avoid collisions, poses close to collision are penalized. The method is implemented and demonstrated on two challenging assembly operations taken from the automotive industry.

  • 82.
    Borén, Sven
    University of Skövde, School of Technology and Society.
    Analys av ventilmekanism i Husabergs motorcykelmotor2009Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The small company Husaberg design and develop motorcycles for competition purpose with the goal to be the best of the best and not be too expensive. The field testing is often used to determine the design, which in some cases will then miss a few essential safety factors. The powerful four-stroke engine is design to ensure high rideability and is based on the old Husqvarna motorcycle engines. To re-calculate and test everything when doing changes would be very expensive and time consuming and the field testing is therefore the most common verification method, even if the fatigue properties can’t be established.The engine has no overspeed protection and that, combined with reaching beyond the yield strength limit (Relmin) in the rocker fingers that pushes down the exhaust poppet valves, does result in fatigue.Husaberg enlarged in 1996 the rocker fingers where they broke off and the consumer claims ceased.

  • 83.
    Bremert, Michael
    et al.
    University of Skövde, School of Technology and Society.
    Persson, Stefan
    University of Skövde, School of Technology and Society.
    Flermålsoptimering och analys av produktionslinje samt identifiering av förbättringsmål2012Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To meet the demands from their customers Volvo Powertrain has set a new production goal for cylinder heads for 13-liter diesels engines. The production lines are built as a flow line of grouped CNC machines, served by a gantry for loading and unloading. The new production goal for one of the production lines, segment 2, is 33 cylinder heads per hour. Volvo Powertrain has also found through the production monitoring-system, Duga, that the waiting time for the loading equipment is a significant amount of the available production time.

    The aim of this project is hence twofold: (1) to verify that the calculations of the waiting time made in Duga are correct; (2) to investigate and propose improvements for the production line in order to achieve the original targeted production goal. This has been done by using simulation and simulation-based optimization technology and for this purpose a generic simulation module of a gantry was made. This project will not answer questions regarding economic consequences, staffing and quality losses in the production line.

    A simulation model has been built in the first phase of the project for a machining cell in Segment 2, which contains one gantry for the loading and unloading operations of four different CNC machining centers connected in series. The simulation model shows that the waiting time of the loading equipment in real time is not as big as what is calculated in Duga. This discrepancy is due to a misleading definition of the waiting time made in Duga.

    The generic gantry module has been used to build a simulation model of Segment 2. Three different optimization runs has been made with an optimization client from the University of Skövde. One of the optimization runs found a solution that matches Volvo Powertrains production goal. From this optimization run one preferred and realistic solution was chosen. The solution includes new levels in buffers along the production line, line balancing and improved availability to the different machines and gantries. The preferred and realistic solution increases the production rate by 10%.

     

  • 84.
    Brolin, Anna
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    An investigation of cognitive aspects affecting human performance in manual assembly2016Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Modern manufacturing systems seem to be shifting from mass production to mass customisation, which means that systems must be able to manage changes in customer demands and requirements, new technology as well as environmental demands. This in turn leads to an increase in product variants that need to be assembled. To handle this issue, well designed and presented information is vital for assembly workers to perform effective and accurate assembly tasks. In this thesis the main focus has been to find factors that affect human performance in manual assembly. A literature review was made on the subject of manufacturing and usability as well as basic cognitive abilities used to utilise information, such as memory. This investigation identified applicable factors for assessing human cognitive performance within the research field of manufacturing. The thesis further investigates how some of these factors are handled in manual assembly, using case studies as well as observational studies. The results show that how material and information are presented to the assembler needs to be considered in order to have a positive effect on the assembly operation. In addition, a full factorial experimental study was conducted to investigate different ways of presenting material and information at the workstation while using mixed assembly mode with product variants. The material presentation factor involved the use of a material rack compared to using an unstructured kit as well as a structured kit and the information presentation factor involved using a text and number instruction compared to a photograph instruction. The results showed that using a kit is favourable compared to the traditional material rack, especially when using a structured kit combined with photographic instruction. Furthermore, the use of unstructured kits can lead to better productivity and reduced perceived workload, compared to a material rack. Although they are perhaps not as good as using a structured kit, they most likely bring a lower cost, such as man-hour consumption and space requirements. However, the number of components in an unstructured kit needs to be considered in order to keep it on a manageable level. As a conclusion, several scenarios were developed in order to understand how different assembly settings can be used in order to improve human performance at the assembly workstation.

  • 85.
    Brolin, Anna
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Brolin, Erik
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Second cycle education program in virtual ergonomics and design2018In: Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018): Volume VII: Ergonomics in Design / [ed] Sebastiano Bagnara, Riccardo Tartaglia, Sara Albolino, Thomas Alexander, Yushi Fujita, Cham: Springer, 2018, Vol. 824, p. 1058-1065Conference paper (Refereed)
    Abstract [en]

    Current product and production development tends to become more complex where principal design decisions are made in very early development phases when product data only exist in virtual formats. To support this virtual product realisation process there exist a number of tools and technologies. Considering ergonomics and human factors in an increasingly complex process with often complex tools requires competent people able to handle multidisciplinary development challenges in a proactive manner. To answer the need for educational programs to cover these issues the School of Engineering Science at University of Skövde has developed a new master (second cycle) program Virtual Ergonomics and Design. The aim with the program is to give students and future product and production developers, necessary knowledge and skills to effectively use virtual tools for analysis, development, and verification of ergonomics and integrate ergonomics and user aspects into the product realisation process. This is achieved through a number of courses that partly forms a core within the subject Virtual product realisation but also provides in-depth knowledge in ergonomics. Students will in a possible future role as design or production engineers have a great influence on ergonomics in manufacturing departments but also better perception of ergonomics, higher motivation and knowledge of support tools and methods for ergonomics integration.

  • 86.
    Brolin, Anna
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Bäckstrand, Gunnar
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Thorvald, Peter
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Case, Keith
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Kitting as an information source in manual assembly2012In: Advances in Ergonomics in Manufacturing / [ed] Stefan Trzcieliński & Waldemar Karwowski, CRC Press, 2012, p. 346-353Chapter in book (Refereed)
    Abstract [en]

    In manual assembly, a strategy to meet the goal of efficient production is the increased use of kitting as a material supply principle. Even though kitting is already implemented in industry, there are still uncertainties regarding the effects of introducing kits, particularly from a human factors perspective.

    This paper presents initial steps in the development of a method to be used for the evaluation of kitting. This from an information source point of view and for studying effects related to productivity and quality. The methodology is projected to act as a foundation for how to carry out a subsequent comprehensive case study. The purpose of the case study is to explore how kitting affects the cognitive workload compared to the ordinary material rack combined with part numbers used in the current manufacturing industry. This is done by measuring productivity; time spent on assembling a product, and quality; number of assembly errors. One step in the methodology development process, which is described in this paper, was to conduct a pilot study, primarily to test the methodology related to the selection of measurement parameters, as well as for getting experiences from running the methodology with real test subjects.

  • 87.
    Brolin, Anna
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, UK.
    Case, Keith
    Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, UK.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Cognitive Aspects Affecting Human Performance in Manual Assembly2016In: Advances in Manufacturing Technology XXX / [ed] Yee Mey Goh, Keith Case, IOS Press, 2016, p. 231-236Conference paper (Refereed)
    Abstract [en]

    This paper concerns the handling of information in assembly work environments. Several studies involving both literature reviews, case studies andobservations were conducted to find factors that affect human performance in manual assembly. The main experiment with 36 subjects used a mixed method design with a quantitative study, including time and errors as dependant measures,a qualitative study, including workload ratings, and a questionnaire. The experiment involved the assembly of a pedal car and the components werepresented using structured kits, unstructured kits and material racks. Assembly information was presented as text & component numbers or photographs, and situations with and without component variation were considered. Among theresults it was found that assembly times and workload ratings were lower when using a kit, whereas using a material rack resulted in perceived decreased workflow and increased stress and frustration. Assembly times and workload ratings were lower when using photographs, whereas using text and numbers increased mental workload.

  • 88.
    Brolin, Anna
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Case, Keith
    Loughborough University, United Kingdom.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Interaction Effects Affecting Human Performance in Manual Assembly2018In: 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, Netherlands: IOS Press, 2018, p. 265-270Conference paper (Refereed)
    Abstract [en]

    This paper presents an experimental study aimed at investigating interaction effects affecting personnel in manual assembly. The main experiment with 36 subjects used a mixed method design which included a quantitative study, including time and errors as dependent measures, and a qualitative study, including workload ratings and a questionnaire. The overall task in the experiment was to assemble components on a pedal car. The main factors involved were assembly information (text & component numbers or photographs), material presentation (using structured kits, unstructured kits and material racks) and component variation (situations with and without component variation). It was found that performance, measured in assembly time, was best when combining photographs with no component variants and when using an unstructured kit.

  • 89.
    Brolin, Anna
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Case, Keith
    Department of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom.
    Experimental study of cognitive aspects affecting human performance in manual assembly2017In: Production & Manufacturing Research, ISSN 2169-3277, Vol. 5, no 1, p. 141-163Article in journal (Refereed)
    Abstract [en]

    This study investigate different ways of presenting material and information at workstations while using mixed assembly mode with product variants. The experimental set up annotated an assembly line involving 36 subjects. The material presentation factor involved the use of a material rack compared to using an unstructured kit as well as a structured kit. The information presentation factor involved using a text and number instruction compared to a photograph instruction, and situations with and without component variation were considered. Results show that assembly times and workload ratings were lower when using a kit, whereas using a material rack resulted in perceived decreased workflow and increased stress and frustration. Moreover, assembly times and workload ratings were lower when using photographs, whereas using text and numbers increased mental workload. The results could be useful when planning work places and production systems in order to obtain a better workflow and an increased human performance. 

  • 90.
    Brolin, Erik
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Chalmers University of Technology.
    Anthropometric diversity and consideration of human capabilities: Methods for virtual product and production development2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Contemporary product and production development is typically carried out with the support of computer tools where the design of products and workstations are originated and evaluated within virtual environments. Ergonomics addresses factors important to consider in the product and production development process to ensure a good fit between humans and the items being designed. Digital human modelling (DHM) tools enable simulations and analyses of ergonomics in virtual environments. Anthropometry is central when using DHM tools for product and production development to ensure that the design fits the intended proportion of the targeted population from a physical perspective. Several methods have been prescribed to consider the anthropometric diversity that exists within human populations. Still many DHM based simulations in product and production development processes are done with approaches that are poor in representing anthropometric diversity. Hence, there is a need for better tools and methods that would support DHM tool users to more effectively and efficiently consider anthropometric diversity in the design process.

    In this thesis current methods for anthropometric diversity considerations have been reviewed and new methods and functionality have been developed and implemented in a DHM tool. Mathematical models have been developed to consider three specific parts important to the consideration of anthropometric diversity: generation of suitable test cases, prediction of missing anthropometric data and implementation of more diverse anthropometric variables such as strength and flexibility. Results show that the proposed methods are accurate and advantageous compared to approaches often used in industry today. The mathematical models for generation of suitable test cases and prediction of missing anthropometric data have been implemented in an anthropometric software module. The module has undergone usability testing with industry DHM tools users. The developed anthropometric module is shown to answer to relevant needs of DHM tool users and fit into the work processes related to DHM simulations and ergonomics analyses utilised in industry today.

  • 91.
    Brolin, Erik
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Consideration of anthropometric diversity: Methods for virtual product and production development2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Ergonomics and Human Factors address factors important to consider in the product and production development process. This is done through a User Centred Design process where focus is put on human-machine interactions. Digital human modelling (DHM) tools provide and facilitate rapid simulations, visualisations and analyses of the human-machine interactions in a virtual environment. Anthropometry, the study of human measurements, is central in DHM simulations due to the necessity of ensuring intended accommodation levels. Several methods have been described to consider the anthropometric diversity that exists within human populations. Still, many simulations are done with few human models, so called manikins, in industry today due to the time consuming processes when working with many manikins in current DHM tools. Hence, there is a need for better tools and methods. To increase the understanding among DHM users there is also a need to illustrate differences in results when using different approaches, and to evaluate the validity of the assumptions that methods for anthropometric diversity consideration are based upon.

    In this thesis current methods for anthropometric diversity considerations have been reviewed and the differences in evaluation results when utilizing different approaches have been analysed. New methods and functionality have been developed and implemented in DHM tools and the possibilities to include more physical characteristics and in turn consider more aspects of human diversity have been explored. Results shows that the proposed methods are advantageous compared to approaches often used in industry today and will, if used, increase the consideration of anthropometric diversity when using DHM tools for the design of products and workplaces.

  • 92.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Hanson, Lars
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Digital human arm models with variation in size, strength and range of motion2014In: / [ed] Masaaki Mochimaru and Makiko Kouchi, 2014Conference paper (Refereed)
    Abstract [en]

    Digital human modelling (DHM) systems can be used to simulate production processes and analyse the human-machine interaction, particularly at early design stages. The human-machine interaction is affected and limited by factors or characteristics belonging to the human user and the machine or product but also the surrounding environment. DHM systems consider in most cases only physical user capabilities and with focus on consideration of body size related anthropometric diversity. However, the human-machine interaction is not only affected by the size and proportions of a user but for example also the user´s muscle strength and range of motion (ROM). This paper describes a study where diversity in strength and ROM, together with diversity in body size, is implemented in the process of creating data for a group of human arm models. A literature study was done to investigate the diversity of strength and ROM and the correlation between such measurements and body size data. The results from the literature study showed that there is little correlation between body size, strength and ROM. The study also showed that there are few published studies where body size, strength and ROM have been tested at the same time. From the literature study, generic correlation coefficients between body size, strength and ROM were synthesized. Using these correlation coefficients and Principal Component Analysis, data for a group of 14 female arm models with varying body size, strength and ROM were calculated. The results show that it is possible to introduce additional variables such as strength and ROM, but also that data of the correlation between body size and other types of anthropometric measurements are scarce. New measurement studies are important to decrease the uncertainties when predicting correlation coefficients between body size, strength and ROM variables.

  • 93.
    Brolin, Erik
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Hanson, Lars
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Örtengren, Roland
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Conditional Regression Model for Prediction of Anthropometric Variables2013In: 2013 Digital human modeling symposium / [ed] Matt Reed, 2013Conference paper (Refereed)
    Abstract [en]

    In digital human modelling (DHM) systems consideration of anthropometry is central. Important functionality in DHM tools is the regression model, i.e. the possibility to predict a complete set of measurements based on a number of defined independent anthropometric variables. The accuracy of a regression model is measured by how well the model predicts dependent variables based on independent variables, i.e. known key anthropometric measurements. In literature, existing regression models often use stature and/or body weight as independent variables in so-called flat regressions models which can produce estimations with large errors when there are low correlations between the independent and dependent variables. This paper suggests a conditional regression model that utilise all known measurements as independent variables when predicting each unknown dependent variable. The conditional regression model is compared to a flat regression model, using stature and weight as independent variables, and a hierarchical regression model that uses geometric and statistical relationships between body measurements to create specific linear regression equations in a hierarchical structure. The accuracy of the models is assessed by evaluating the coefficient of determination, R2 and the root-mean-square deviation (RMSD). The results from the study show that using a conditional regression model that makes use of all known variables to predict the values of unknown measurements is advantageous compared to the flat and hierarchical regression models. Both the conditional linear regression model and the hierarchical regression model have the advantage that when more measurements are included the models will give a better prediction of the unknown measurements compared to the flat regression model based on stature and weight. A conditional linear regression model has the additional advantage that any measurement can be used as independent variable. This gives the possibility to only include measurements that have a direct connection to the design dimensions being sought. Utilising the conditional regression model would create digital manikins with enhanced accuracy that would produce more realistic and accurate simulations and evaluations when using DHM tools for the design of products and workplaces.

  • 94.
    Brolin, Erik
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Hanson, Lars
    Industrial Development, Scania CV, Södertalje, Sweden / Chalmers University of Technology, Gothenburg, Sweden.
    Description of boundary case methodology for anthropometric diversity consideration2012In: International Journal of Human Factors Modelling and Simulation, ISSN 1742-5549, Vol. 3, no 2, p. 204-223Article in journal (Refereed)
    Abstract [en]

    This paper describes and evaluates the boundary case methodology for the simultaneous consideration of variance for a number of selected anthropometric variables. The methodology includes the calculation of key dimension values for extreme but likely anthropometric measurement combinations. This data can be applied when utilising digital human modelling (DHM) tools for proactive design work and entered as input data when representative manikins are defined. The mathematical procedure is clearly described and exemplified to demonstrate how to use the methodology in design work. The outcome of the method is illustrated and compared using several different cases where the number of measurements is varied and where principal component analysis (PCA) is used to reduce the number of dimensions in one case. The paper demonstrates that the proposed boundary case method is advantageous compared to approaches based on the use of univariate percentile data in design.

  • 95.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Design of a Digital Human Modelling Module for Consideration of Anthropometric Diversity2014In: Advances in Applied Digital Human Modeling / [ed] Vincent Duffy, AHFE Conference , 2014, p. 114-120Conference paper (Refereed)
  • 96.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Örtengren, Roland
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Adaptive regression model for synthesizing anthropometric population data2017In: International Journal of Industrial Ergonomics, ISSN 0169-8141, E-ISSN 1872-8219, Vol. 59, p. 46-53Article in journal (Refereed)
    Abstract [en]

    This paper presents the development of an adaptive linear regression model for synthesizing of missing anthropometric population data based on a flexible set of known predictive data. The method is based on a conditional regression model and includes use of principal component analysis, to reduce effects of multicollinearity between selected predictive measurements, and incorporation of a stochastic component, using the partial correlation coefficients between predicted measurements. In addition, skewness of the distributions of the dependent variables is considered when incorporating the stochastic components. Results from the study show that the proposed regression models for synthesizing population data give valid results with small errors of the compared percentile values. However, higher accuracy was not achieved when the number of measurements used as independent variables was increased compared to using only stature and weight as independent variables. This indicates problems with multicollinearity that principal component regression were not able to overcome. Descriptive statistics such as mean and standard deviation values together with correlation coefficients is sufficient to perform the conditional regression procedure. However, to incorporate a stochastic component when using principal component regression requires raw data on an individual level.

    Relevance to industry

    When developing products, workplaces or systems, it is of great importance to consider the anthropometric diversity of the intended users. The proposed regression model offers a procedure that gives valid results, maintains the correlation between the measurements that are predicted and is adaptable regarding which, and number of, predictive measurements that are selected.

  • 97.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Industrial Development, Scania CV, Södertälje.
    Örtengren, Roland
    Chalmers University of Technology, Gothenburg.
    Development and evaluation of an anthropometric module for digital human modelling systems2019In: International Journal of Human Factors Modelling and Simulation, ISSN 1742-5549, Vol. 7, no 1, p. 47-70Article in journal (Refereed)
    Abstract [en]

    This paper presents the development of a software module and a graphical user interface which aims to support the definition of anthropometry of manikins in a digital human modelling (DHM) tool. The module is developed from user interviews and literature studies, as well as mathematical methods for anthropometric diversity consideration. The module has functionality to create both single manikins and manikin families, where it is possible to combine or analyse different population datasets simultaneously. The developed module and its interface have been evaluated via focus group interviews and usability tests by DHM tool users. Results from the studies show that the developed module and its interface has relevant functionality, fits well into industrial work processes, and is easy to use. The study also identifies possibilities to further increase usability.

  • 98.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Industrial Development, Scania, Scania CV, Södertälje, Sweden / Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Örtengren, Roland
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Generation and evaluation of distributed cases by clustering of diverse anthropometric data2016In: International Journal of Human Factors Modelling and Simulation, ISSN 1742-5557, Vol. 5, no 3, p. 210-229Article in journal (Refereed)
    Abstract [en]

    This paper describes a study where diversity in body size, strength and joint range of motion, together with diversity in other capability measurements, is included in the process of generating data for a group of test cases using cluster analysis. Descriptive statistics and correlation data was acquired for 15 variables for different age groups and both sexes. Based on this data, a population of 10,000 individuals was synthesised using correlated random numbers. The synthesised data was used in cluster analyses where three different clustering algorithms were applied and evaluated; hierarchical clustering, k-means clustering and Gaussian mixture distribution clustering. Results from the study show that the three clustering algorithms produce groups of test cases with different characteristics, where the hierarchical and k-means algorithm give the most diverse results and where the Gaussian mixture distribution gives results that are in between the first two.

  • 99.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Mahdavian, Nafise
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Industrial Development, Scania CV, Södertälje.
    Johansson, Joakim
    Bombardier Transportation Sweden AB, Västerås.
    Possibilities and challenges for proactive manufacturing ergonomics2019In: Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018): Volume VIII: Ergonomics and Human Factors in Manufacturing, Agriculture, Building and Construction, Sustainable Development and Mining / [ed] Sebastiano Bagnara, Riccardo Tartaglia, Sara Albolino, Thomas Alexander, Yushi Fujita, Cham: Springer, 2019, Vol. 825, p. 11-20Conference paper (Refereed)
    Abstract [en]

    This paper identifies and describes product development activities where ergonomics issues could be considered and illustrates how that could be done through a number of different approaches. The study is divided into two parts where an interview study is done to identify where in a product development process consideration of ergonomics issues are or could be done. The second part of the study includes an observation, motion capture and simulation study of current manufacturing operations to evaluate and compare three different assessment approaches; observational based ergonomics evaluation, usages of motion capture data and DHM simulation and evaluation. The results shows the importance of consideration of ergonomics in early development phases and that the ergonomics assessment process is integrated in the overall product and production development process.

  • 100.
    Brown González, Lorena
    et al.
    University of Skövde, School of Engineering Science.
    Palacios Certucha, Rodrigo
    University of Skövde, School of Engineering Science.
    The design of a playground toy2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The report describes the design of a safe (within EU regulations), ergonomic, attractive, sustainable, versatile and interactive playground toy for children from ages 7 to 11. The product aims to help children develop in different aspects: physical, emotional, social and mental, in a sustainable environment. This was developed from the identification and exploration of the factors that influence the design of playground toys. The design process was divided in the following main stages: an initial research of information, the interpretation of this data, the development of a concept, a test stage and the results. During the research, teachers and parents were interviewed and children were observed. Relevant information was also gathered. For the development, a set of creative techniques were applied and finally tested. Modifications based on the test were made to reach an accurate design. The work done was successful to the extent established initially; although, it can be subject to improvement. The main limit was that no tests were performed on a physical prototype, therefore, there is information not yet gathered and tests that would prove if some of the assumptions were true or false.  

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