| 1. |
- Vidner, Olle, 1990-
(author)
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On Multi-Disciplinary Optimization in Engineer-to-Order Product Configuration
- 2023
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Licentiate thesis (other academic/artistic)abstract
- Customized products are becoming increasingly common, and increasingly important for maintaining a competitive advantage in certain industries. Being able to quickly and accurately respond to unique customer requirements can provide a competitive edge or even be the only path to survival. In practice, configurators are commonly used to manage the customization process, gathering the customer’s requirements and suggesting feasible solutions to the customer’s problem.Fostering and maintaining a viable product customization offering is not easy. A particularly challenging category of products is one where an extensive engineering effort might be needed to even produce a reliable estimate of the product’s price. These products are usually referred to as engineer-to-order (ETO) products.Prior work has pointed out the potential of using optimization as part of configuration solutions for ETO products, but the literature is limited in its extent and does not clearly prescribe how to structure and approach such solutions.This thesis outlines a conceptual and technical architecture for implementing optimization-based configuration solutions. Reusable primitives for supporting the routines involved in this architecture are provided. These findings are verified through application and evaluation within two industrial case studies, also yielding important industrial needs to cover in the future research and development of the proposed framework. By examining three additional case studies, common issues in the development and deployment of design automation (DA) systems are identified.Successful implementation of the proposed framework for optimization-based configurators can lead to two main benefits. First, engineering configurator prototypes can be developed rapidly, to test the viability of configurator projects – a category of projects prone to expensive failures. Second, optimization-based configurators can be used to support rapid design space exploration in early product development stages, leading to enhanced product knowledge in a critical phase, and in turn, increased product value.
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| 2. |
- Paulson, Fredrik, 1976-
(author)
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Inclusion of sustainability aspects in product development at manufacturing companies
- 2018
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Licentiate thesis (other academic/artistic)abstract
- Due to current consumption and production patterns of products, pressure on already constrained natural resources, an increasing global population, increasing concentrations of greenhouse gases in the atmosphere and reduced access to clean water globally, studying manufacturing companies’ inclusion of sustainability aspects in their product development becomes important.The aim of this thesis is to expand current knowledge on the inclusion of sustainability aspects in product development at manufacturing companies. More specifically, the expansion of current knowledge covers how manufacturing companies include sustainability aspects in product development, the challenges manufacturing companies may face when including sustainability aspects in product development, and the reasons for these challenges.To fulfil this aim, a literature study and a multiple case study were conducted at two international, listed, manufacturing companies in Sweden. Empirical data was collected using semi-structured interviews with two employees at each company and by analyzing the companies’ latest sustainability report.Empirical results include two context-dependent descriptions of how manufacturing companies include sustainability aspects in product development, 21 challenges the companies face, and 14 reasons for those challenges.Conclusions include: (1) the role of conventional methods when including sustainability aspects in product development has been largely ignored in prior research; (2) a company’s product owner influences the inclusion of sustainability aspects in product development, and in product requirements in particular; (3) the following three challenges are proposed incorporated in a comprehensive framework of challenges that has been developed in prior research:Making suppliers fulfil the sustainability requirements that are placed on them. Transforming sustainability aspects, or general goals, into measurable requirements that contribute to reduced environmental impact from products while at the same time contributing to competitive profit.Identifying how to reach economic goals more efficiently with a more sustainable initiative or solution than other initiatives.
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| 3. |
- Wehlin, Camilla, 1992-
(author)
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Optimization-Based Configurators in the Product Development Process
- 2021
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Licentiate thesis (other academic/artistic)abstract
- Requirements from the market on customer responsiveness and pressure on the environmental profiles of companies, both internally and externally, are challenging companies to amend their processes in all possible aspects in order to stay competitive. For product development companies, the challenges often lie in developing and delivering products rapidly, customized and meeting the set requirements. For highly customized products, mass customization is a term describing a company setting in which products meet each customer’s individual requirements but are still produced and delivered at near mass-production efficiency. The concept of mass customization is becoming a prerequisite for the survival of companies within this niche. For more complex engineering products, the complexity increases as new technology is introduced, which needs to be integrated to increase the product’s performance at a rapid pace. Also for complex products, the level of customization is increasing, which motivates the support of tools enabling an increase in customization.In both mass customized and complex products, the obstacles to overcome are the repetitive resource inefficient work, knowledge capture and reuse, uncoordinated processes, and a high number of iterations between departments within the company. This often boils down to the well-established so-called design paradox describing the lack of knowledge about a product and process in the early stages of design, where the design freedom is still high. As knowledge increases throughout the process, the design freedom in contrast shrinks, and the costs of changes increase exponentially. Design automation, design optimization and the use of configurators are all methods used to reduce repetitive work, increase and capture knowledge, and integrate the product development process.This thesis presents how configurators based on optimization can be used and integrated into the product development process of engineering intensive configurable products and components, such as engineer-to-order (ETO) products. Design automation and design optimization have been identified as key building blocks to extend the use of configurators. This has been done in two different application cases within two different research projects, to evaluate how these configurator systems may be modeled and utilized. The first application case concerns the automation of hose routing in vehicles and the second application case concerns spiral staircases intended for mass customization.
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| 4. |
- Amadori, Kristian
(author)
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Geometry Based Design Automation : Applied to Aircraft Modelling and Optimization
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Product development processes are continuously challenged by demands for increased efficiency. As engineering products become more and more complex, efficient tools and methods for integrated and automated design are needed throughout the development process. Multidisciplinary Design Optimization (MDO) is one promising technique that has the potential to drastically improve concurrent design. MDO frameworks combine several disciplinary models with the aim of gaining a holistic perspective of a system, while capturing the synergies between different subsystems. Among all disciplines, the geometric model is recognized as playing a key role, because it collects most of the data required to any other disciplinary analysis. In the present thesis, methodologies to enable multidisciplinary optimization in early aircraft design phases are studied. In particular, the research aims at putting the CAD geometric model in the loop. This requires the ability to automatically generate or update the geometric model, here referred to as geometry-based design automation.The thesis proposes the use of Knowledge Based Engineering (KBE) techniques to achieve design reuse and automation. In particular, so called High Level CAD templates (HLCts) are suggested to automate geometry generation and updates. HLCts can be compared to parametric LEGO® blocks containing a set of design and analysis parameters. These are produced and stored in libraries, giving engineers or a computer agent the possibility to first topologically select the templates and then modify the shape of each template parametrically.Since parameterization is central to modelling by means of HLCts, a thorough analysis of the subject is also performed. In most of the literature on MDO and KBE two recurring requirements concerning the geometrical model are expressed: the model should be flexible and robust. However, these requirements have never been properly formulated or defined. Hence, in the thesis a mathematical formulation for geometry model robustness and flexibility are proposed. These formulations ultimately allow the performance of geometric models to be precisely measured and compared.Finally, a prototyping and validation process is presented. The aim is to quickly and cost-effectively validate analytical results from an MDO process. The proposed process adopts different manufacturing techniques depending on the size and purpose of the intended prototype. In the last part of the thesis, three application examples are presented. The examples are chosen from research projects that have been carried out at Linköping University and show how the proposed theoretical results have been successfully employed in practice.
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| 5. |
- Andersson, Henric, 1963-
(author)
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Variability and Customization of Simulator Products : A Product Line Approach in Model Based Systems Engineering
- 2012
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Doctoral thesis (other academic/artistic)abstract
- AIRCRAFT DEVELOPERS, like other organizations within development and manufacturing, are experiencing increasing complexity in their products and growing competition in the global market. Products are built from increasingly advanced technologies and their mechanical, electronic, and software parts grow in number and become more interconnected. Different approaches are used to manage information and knowledge of products in various stages of their lifecycle."Reuse" and "Model Based Development" are two prominent trends for improving industrial development efficiency. The product line approach is used to reduce the time to create product variants by reusing components. The model based approach provides means to capture knowledge about a system in the early lifecycle stages for usage throughout its entire lifetime. It also enables structured data management as a basis for analysis, automation, and team collaboration for efficient management of large systems and families of products.This work is focused on the combination of methods and techniques within;modeling and simulation-based development, and(re)use of simulation models through the product line concept.With increasing computational performance and more efficient techniques/tools for building simulation models, the number of models increases, and their usage ranges from concept evaluation to end-user training. The activities related to model verification and validation contribute to a large part of the overall cost for development and maintenance of simulation models. The studied methodology aims to reduce the number of similar models created by different teams during design, testing, and end-user support of industrial products.Results of the work include evaluation of a configurator to customize and integrate simulation models for different types of aircraft simulators that are part of a simulator product family. Furthermore, contribution comprises results where constraints in the primary product family (aircraft) govern the configuration space of the secondary product family (simulators). Evaluation of the proposed methodology was carried out in cooperation with the simulator department for the 39 Gripen fighter aircraft at Saab Aeronautics.
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| 6. |
- Andersson, Torbjörn
(author)
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Aesthetic Flexibility : Modularity of Visual Form in Product Portfolios and Branded Products
- 2016
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Licentiate thesis (other academic/artistic)abstract
- The increase in competition amongst companies that produce complex or large product portfolios has created a need to utilise modularity strategies not only to flexibly manage technical complexity in a costeffective manner but also for visual appearance. This research aims to understand how the visual appearance of products is affected by modular product development strategies. Specifically, the aim is to understand how such strategies induce constraints and generate possibilities for management of visual appearance in the design process.Five studies have been conducted during the course of this licentiate thesis. Two were conducted with professionals and students in design, while the remaining three are theoretical studies based on findings in the literature, theory building, and experimental research. The goal has been to investigate how designers work when they are put to the task of changing and developing the designs of complex products that are part of a portfolio. The challenge has been to study what suitable strategies exist that manage complex products and product brands, then investigate how these influence designers’ practices.The first study examined how coherence towards a product category influences the design of new products. The outcome of the study was a method to explore visual coherence and diversity in the appearance of a product category.The remaining four studies investigated how modularity, brand management and the redesign of product portfolios influence a design process. The second study described a design phenomenon known as aesthetic flexibility, which was further explored in studies three and five. The outcome from these studies was a proposal for four aesthetic flexibility strategies.The fourth study investigated in what way portfolio extension strategies found in brand management and design research are related, and how such strategies influence aesthetic flexibility. The results from study four were illustrated as a model.The main contribution of this work is the phenomenon of ‘aesthetic flexibility’, which helps understand the factors that influence designers when working with branded modular products. Understanding visual flexibility serves as a starting point in further investigations of how different development strategies affect the possibilities for visual product design.The findings of this work serve to illustrate and explain a complex and multi-facetted design phenomenon which many designers manage more or less intuitively today, thus advancing academics’, teachers’ and professional designers’ understanding of the field.
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| 7. |
- Andersson, Torbjörn, 1976-
(author)
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Aesthetic Flexibility : In Industrial Design Practice
- 2021
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Doctoral thesis (other academic/artistic)abstract
- Competition among companies that produce complex or large product portfolios has created a need to use modularity strategies not only to flexibly manage technical complexity in a cost-effective manner but also to produce visually appealing products. This research aims to understand how the visual appearance of products is affected by modular product development strategies and creates coherent product brands. Thus, this study examines the intersection of design aesthetics, product portfolio management, product brand management, and design management. Specifically, this study aims to understand how such strategies constrain and generate possibilities when the industrial design process concerns itself with visual appearance. The main research approach has been qualitative multi-case methodology (Miles et al, 2014; Eisenhardt, 1989) and design theory building (Chakrabarti and Blessing, 2016) that collects data through interviews, experimentation, and theoretical studies based on findings in the literature. Sixteen face-to-face interviews were conducted with design vice presidents, senior designers, and senior design engineers at five Swedish manufacturers from the automotive, MedTech, consumer goods, commercial vehicles, and materials handling industries. This approach has resulted in the description of three theoretical models and a design method, product gist, for investigating prototypicality in a product category. Aesthetic flexibility reflects the requirement that under certain circumstances an industrial designer has to plan for future (as yet unknown) changes in a design. Each of the three theoretical models has a different focus: one model describes three ways manufacturing companies organise a strategic in-house design function; one model describes how design decisions are made on a general level through an intuitive and knowledge-based judgment process; and one model describes the strategies a manager needs to consider when developing an existing product portfolio and how the strategies influence industrial design practice. Understanding visual flexibility serves as a starting point for further investigations of how development strategies affect visual product design. This understanding provides industrial designers insight into how they can develop product systems that share design components across product lines to promote brand identity. The findings of this work illustrate and explain a complex and multi-facetted design phenomenon that many designers manage more or less intuitively today; therefore, this study advances the understanding of the field for academics, teachers, and professional designers.
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| 8. |
- Blissing, Björn, 1978-
(author)
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Driving in Virtual Reality : Requirements for automotive research and development
- 2020
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Doctoral thesis (other academic/artistic)abstract
- In the last decades, there has been a substantial increase in the development of complex active safety systems for automotive vehicles. These systems need to be tested for verification and validation to ensure that the system intervenes in the correct situations using the correct measures. There are multiple methods available to perform such testing. Software-in-the-loop and hardware-in-the-loop testing offer effective driverless testing. Other methods increase the fidelity by including human drivers, such as driving simulators and experiments performed at test tracks.This thesis examines vehicle-in-the-loop testing, an innovative method where the driver of a real vehicle wears a head-mounted display that displays virtual targets. This method combines the benefits of driving simulators with the benefits of using a real vehicle on a test track. Driving simulators offer repeatability, safety, and the possibility of complex interactions between actors. In contrast, the real vehicle provides the correct vehicle dynamics and motion feedback.There is a need to know how the technology behind the method might influence the results from vehicle-in-the-loop testing. Two techniques for vehicle-in-the-loop systems are studied. The first involves video-see through head-mounted displays, where the focus of the research is on the effects of visual latency on driving behavior. The results show that lateral driving behavior changes with added latency, but longitudinal behavior appears unaffected. The second system uses an opaque head-mounted display in an entirely virtual world. The research shows that this solution changes speed perception and results in a significant degradation in performance of tasks dependent on visual acuity.This research presents results that are relevant to consider when developing vehicle-in-the-loop platforms. The results are also applicable when choosing scenarios for this test method.
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| 9. |
- Dudas, Catarina, 1972-
(author)
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Learning from Multi-Objective Optimization of Production Systems : A method for analyzing solution sets from multi-objective optimization
- 2014
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Doctoral thesis (other academic/artistic)abstract
- The process of multi-objective optimization involves finding optimal solutions to several objective functions. However, these are typically in conflict with each other in many real-world problems, such as production system design. Advanced post-optimization analysis can be used to provide the decision maker with information about the underlying system. The analysis can be based on the combination of simulation-based multi-objective optimization and learning from the obtained solution set. The goal of the analysis is to gain a deeper understanding of the problem at hand, to systematically explore and evaluate different alternatives, and to generate essential information and knowledge to support the decision maker to make more informed decisions in order to optimize the performance of the production system as a whole.The aim of this work is to explore the possibilities on how post-optimization analysis can be used in order to provide the decision maker with essential information about an underlying system and in what way this information can be presented. The analysis is mainly done on production system development problems, but may also be transferred to other application areas.The research process of the thesis has been iterative, and the initial approach for post-optimization analysis has been refined several times. The distance-based approach developed in the thesis is used to allow the extraction of information about the characteristics close to a user-defined reference point. The extracted rules are presented to the decision maker both visually, by mapping the rules to the objective space, and textually. The method has been applied to several industrial cases for proof-by-demonstration as well as to an artificial case with information known beforehand to verify the distance-based approach, and the extracted rules have also been used to limit the search space in the optimization. The major finding in the thesis is that to learn from optimization solution sets of production system problems with stochastic behavior, a distance-based approach is advantageous compared with a binary classification of optimal vs. non-optimal solutions.
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| 10. |
- Gustafsson, Erik, 1993-
(author)
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Exploring Data-Driven Methods to Enhance Usability of Design Optimization
- 2022
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Licentiate thesis (other academic/artistic)abstract
- Developing high-performing products at a low cost while keeping development time down is increasingly important in today’s competitive market. The current state presents a need for efficient product development processes. One of the challenges is knowledge often being limited in early stages where the cost of making changes is still relatively low. As the process progresses more knowledge is gained to better support decisions; however the cost of making changes increases, limiting the design freedom. To increase knowledge while retaining design freedom, several computer-based tools are available to both generate and evaluate designs in order to make iterations faster and more accurate.Design Optimization (DO) can be utilized to explore the design space and find optimal designs. A Computer-Aided Design (CAD) model is often required as input to analysis tools evaluating the designs. By utilizing Design Automation (DA) several tasks involved in creation and modification of CAD models can be automated. For this reason, DA is sometimes considered an enabler for DO although its use is far wider, covering several aspects of the design process mainly focusing on automating repetitive and routine tasks.Machine Learning and other data-driven methods are becoming increasingly viable in the context of DO and DA. This thesis explores the use of data-driven methods to enhance the usability of DO in different ways such as a faster process, new use-cases, or a more integrated and automated process. Literature in the area is reviewed, identifying applications, trends and challenges. Furthermore, two support tools are developed, incorporating data-driven methods tied to an industrial case. The applications focus on parameterizing geometry and predicting design performance respectively. Potential benefits, limitations, and challenges are discussed based on the literature review and insights from the two support tools. The focus of the thesis is mainly on how data-driven methods can facilitate automation and integration in the design process, specifically for complex products requiring significant engineering efforts.
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