| 1. |
- Ask, Andréas, 1977-
(author)
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Factory-in-a-Box : an Enabler for Flexibility in Manufacturing Systems
- 2006
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Licentiate thesis (other academic/artistic)abstract
- AT PRESENT, many markets are characterized by a fast pace of change, as well as a high internationally enlarged competition. Since the conception of Mass Customization emerged in the late 1980´s, many companies within the manufacturing industry have been striving to fulfill this vision by increasing the flexibility within their manufacturing system. However, although there are many manufacturing theories that describe theoretical solutions to mass customization, but there is still a lack of practical enablers that can realize the conception.In January 2005, the Swedish Foundation for Strategic Research started the project Factory-in-a-Box. There, the key characteristic is to realize is the concept of modular production units that are flexible, mobile and quick to ramp-up. This licentiate thesis is a part of the Factory-in-a-Box project, and its objective is to investigate if and how the Factory-in-a-box concept is an enabler to realize flexibility in manufacturing systems.The outcome of this research work indicates that the Factory-in-a-Box concept is a plausible solution that goes in line with previous research and future challenges within the manufacturing industry. The Factory-in-a-Box concept offers possibilities for a more flexible and responsive manufacturing system, which also unwrap new business possibilities, increased automation, and entering new markets. To succeed in implementing the Factory-in-a-Box concept in a manufacturing system some key generic requirements have been identified.The research project concludes that mobile manufacturing systems in general and the Factory-in-a-Box concept in particular offer new possibilities to the manufacturing industry. Also, the concept is not limited to the manufacturing industry, there are a wide range of applications where the concept could be useful, for example within the construction industry.
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| 2. |
- Andersson, Carina, 1970-
(author)
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Informationsdesign i tillståndsövervakning : En studie av ett bildskärmsbaserat användargränssnitt för tillståndsövervakning och tillståndsbaserat underhåll
- 2010
-
Doctoral thesis (other academic/artistic)abstract
- This research concerns the information design and visual design of graphical user interfaces (GUI) in the condition monitoring and condition-based maintenance (CBM) of production equipment. It also concerns various communicative aspects of a GUI, which is used to monitor the condition of assets. It applies to one Swedish vendor and its intentions to design information. In addition, it applies to the interaction between the GUI and its individual visual elements, as well as the communication between the GUI and the users (in four Swedish paper mills).The research is performed as a single case study. Interviews and observations have been the main methods for data collection. Empirical data is analyzed with methods inferred to semiotics, rhetoric and narratology. Theories in information science and regarding remediation are used to interpret the user interface design.The key conclusion is that there are no less than five different forms of information, all important when determining the conditions of assets. These information forms include the words, images and shapes in the GUI, the machine components and peripherals equipment, the information that takes form when personnel communicate machine conditions, the personnel’s subjective associations, and the information forms that relate to the personnel's actions and interactions.Preventive technicians interpret the GUI-information individually and collectively in relation to these information forms, which influence their interpretation and understanding of the GUI information. Social media in the GUI makes it possible to represent essential information that takes form when employees communicate a machine’s condition. Photographs may represent information forms as a machine’s components, peripherals, and local environment change over time. Moreover, preventative technicians may use diagrams and photographs in the GUI to change attitudes among the personnel at the mills and convince them, for example, of a machine’s condition or the effectiveness of CBM as maintenance policy.
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| 3. |
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| 4. |
- Ekman, Björn, et al.
(author)
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Skala upp den befintliga digitala vården i Sverige
- 2020
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In: Dagens Medicin. - Stockholm : Bonnier. - 1104-7488.
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Journal article (pop. science, debate, etc.)abstract
- Ge Socialstyrelsen ett nationellt uppdrag att beställa och ersätta vårdgivare av digital vård, föreslår en grupp forskare med anledning av covid-19.
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| 5. |
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| 6. |
- Elfving, Sofi, 1978-
(author)
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Managing Collaborative Product Development : A Model for Identifying Key Factors in Product Development Projects
- 2007
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Doctoral thesis (other academic/artistic)abstract
- The increasing complexity of products and systems today has forced new processes, methods, and tools for managing the development of products. It has also forced the development of complex organisations and diverse relationships among functions and peoples within product development organisations. This implies a need for integrated processes. There is a need to study collaborative product development (CPD) from a holistic perspective, where internal as well as external collaboration are studied as integrated parts of CPD settings.Thus, the main purpose of the research project is to facilitate the efficient execution of collaborative product development projects in the manufacturing industry. Further, the objective is to provide a supporting model for analysing and setting up projects in CPD settings. This will enable successful product development in terms of lowering costs, increasing the perceived quality of the product, and improving the timing to market. The focus is on the CPD projects, linking internal and external collaboration.A systems approach is applied to the research project to obtain the holistic view needed for addressing the CPD setting. Within the research project, case study research is used as the primary method when gathering empirics. The results from four case studies are tested and analysed in a concluding survey.The results show that shared visions and goals, the decision-making process, tools and methods, requirement management, and involvement are the most important factors for efficient CPD projects. If the collaborative complexity is high, the first four factors are especially important. The results are presented in a model to be used as a support when setting-up and managing CPD projects. The model is applied together with a process for managing CPD projects.
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| 7. |
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| 8. |
- Eriksson, Joakim, 1977-
(author)
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Coping with decisions on deviations in complex product development projects
- 2012
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Doctoral thesis (other academic/artistic)abstract
- A strong need for resource efficiency within manufacturing companies have been driven extensively through pro-active planning and methods which have naturally resulted in an increased amount of strong couplings between product development projects, their activities, and resources. These strong couplings mean a high level of complexity where deviations are likely to occur on a regular basis which can spread quickly and have far reaching consequences. Praxis related to treatment of such deviations in product development projects has not been widely discussed. The subsequent question is therefore How are decisions on managing deviations made in practice?A Practice approach has been adopted in this research and led on to the use of context sensitive research methods in order to collect relevant data. The main amount of data has been gathered through one year of participant observations and document retrieval in a product development project. Also, a large amount of interviews have been used as a method for collecting data.38 deviations have been analysed through the identification of praxis which has been primarily analysed by three theories. The first theory, decision roles, has been used to clarify the different types of uncertainties people within complex product development projects need to manage in practice. The second theory, loosely coupled systems, shows how temporary organizing by loose couplings enables parallel management of both planned and unplanned activities when deviations occur. The third theory, Sensemaking, have been used to characterise processes related to different types of uncertainties.Conclusions are drawn regarding how people acts related to deviations are directly dependent on the types of uncertainties of the context as well as the situation itself. Uncertainties regarding choices, responsibilities, mobilization, and legitimization combined with the temporary organization leads to certain praxis patterns. The patterns can be used by project managers and other decision makers as a way of discussing temporary organization and how process emerge within the organization today, and how they would like resulting processes to be managed when deviations occur.
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| 9. |
- Eriksson, Joakim, 1977-, et al.
(author)
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Decisions on managing project deviations in practice
- 2024
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In: International Journal of Project Organisation and Management. - : Inderscience Publishers. - 1740-2891 .- 1740-2905.
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Journal article (peer-reviewed)abstract
- This paper presents the results of a case study aimed at investigating how decisions are made on managing deviations in complex product development projects. The results are based on the analysis of data collected from participant observations, as well as interviews with project managers from seven large manufacturing companies. The data is analysed according to four types of sensemaking processes. This research examines why these processes are used in different situations and further explore their characteristics and at their relationship with the different roles decisions play in organizations. The factors driving controlled and uncontrolled sensemaking are also examined. This research contributes to knowledge of how project managers use different praxes to manage deviations in complex, socially and politically sensitive environments. The results can be used by decision makers within complex product development in order to assist them in managing deviations, proactively as well as reactively.
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| 10. |
- Eriksson, Joakim, 1977-, et al.
(author)
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EFFICIENT DECISION-MAKING IN PRODUCT DEVELOPMENT
- 2007
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In: Proceedings of ICED 2007, the 16th International Conference on Engineering Design, vol DS 42. - 1904670024 - 9781904670025
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Conference paper (peer-reviewed)abstract
- Product development projects need to be managed in a timely and efficient manner in the present competitive business environment. The authors of this work argue that the commonly used product development models do not fully meet this demand, and the decision-making process needs to be made explicit. This work mainly focuses on the product development process. Two companies were studied using case study research. The aim of the case study was to identify key factors affecting the decision-making process in product development. The type of collaboration used in these two companies was also investigated in order to identify the influence it had on the decision-making process of each. The two companies had different views of the decision-making process which were related to their level of development process knowledge. Common factors affecting the decision-making process in product development were divided into ten categories: (1) Handling of requirements, (2) Experience of projects, (3) Organizational aspects, (4) Project management, (5) Top management, (6) Knowledge, (7) Risk management, (8) Information systems, (9) Communication, and (10) Change management.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
- Fagerström, Björn, et al.
(author)
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Efficient collaboration between main and sub-suppliers
- 2002
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In: Computers in industry. - 0166-3615 .- 1872-6194. ; 49:1, s. 25-35
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Journal article (peer-reviewed)abstract
- Many sub-suppliers are interested in closer integration with main suppliers for product development. However, main suppliers have much work that needs to be coordinated, and close integration with suppliers is used only when it is required, and when additional value is created through integration. The main objective of this paper, is therefore, to discuss different supplier roles and increase the understanding of how suppliers can be integrated with the main supplier. The result is based on a case study with one main supplier and nine of its sub-suppliers, where the main supplier develops, assembles, and delivers a complete, complex product to the customer, and the sub-suppliers develop and manufacture sub-systems for the main supplier. The results give new insights into what the sub-suppliers could do in order to improve integration with the main supplier.
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| 15. |
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| 16. |
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| 17. |
- Fagerström, Björn, et al.
(author)
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Knowledge Management in Collaborative Product Development
- 2002
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In: Systems Engineering. - : Wiley. - 1098-1241 .- 1520-6858. ; 5:4, s. 274-285
-
Journal article (peer-reviewed)abstract
- Today, an increasing amount of main suppliers are using sub-suppliers to perform different tasks in the product development process. As a result, the knowledge needed to develop a new product is distributed among many actors. Knowledge management is a comprehensive term for providing the right piece of knowledge to the right people at the right time. This paper deals mainly with the question of how knowledge is managed in collaborative product development between main and subsuppliers (system level). The results are based on a case study with one main supplier and ten of their subsuppliers, in which the main suppler develops, assembles, and delivers a whole, complex product to the customer. The study shows that the subsuppliers' knowledge and experiences are not fully utilized in their relationship with the main supplier. Finally, some different ways of working are discussed in the paper's recommendation section, to improve the knowledge exchange between main and sub-suppliers.
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| 18. |
- Fagerström, Björn, 1966
(author)
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Managing Distributed Product Development. An Information and Knowledge Perspective
- 2004
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Doctoral thesis (other academic/artistic)abstract
- Product development is one of the most important activities in an industrial company, in order to strengthen the position at the market and achieve competitive advantages. Companies are under pressure to bring new products to the market faster, at a lower cost and with increased performance. In this demanding environment, companies frequently focus on their core competencies, search for external complementary knowledge and look for partners who can share the risk and cost, in order to stay competitive. Increased outsourcing results in a need to co-ordinate the work between multiple actors. Distributed product development is also dependent on the ability to manage information exchange between interfaces for upstream and downstream tasks, different sub-systems and different organisational functions. The overall objective of this research is to enhance the knowledge of how sub-suppliers can be integrated with main suppliers and to provide guidelines and support for distributed product development. This research focuses on the distributed product development system, primarily on the relationship between main and sub-suppliers. Increased complexity stresses the need for models and methods that can be used for design teams to develop a shared understanding. In order to deal with this demand a holistic view is needed. This research applies a combination of systems theory and an actors' approach, with the aim of dealing with complex problems. The results of this research are based on six different case studies, presented in seven appended papers. This research presents an interface model that can be used for main and sub-suppliers, with a structured procedure for improving their collaboration. This research work also contains increased knowledge for what the sub-suppliers can do in order to be integrated with the main supplier. A model for analysing the knowledge process between main and sub-suppliers has been developed. The potential for better utilising the sub-suppliers' knowledge has been confirmed. A phenomena model has been developed that could support distributed product development. The model aims for a common understanding of involved stakeholders, requirements, functions and sub-systems during the design of the product. The knowledge of integrated product and process modelling has been further developed, in order to bridge, or at least minimise, the gap between product and process domain. The results have industrial relevance as well. The thesis primarily addresses those managers, project managers, decisions-makers, planners and designers who are, or expect to be, responsible for distributed product development projects.
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| 19. |
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| 20. |
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| 21. |
- Fritz, Björn, et al.
(author)
-
Konsten i nätverket lever sitt egna liv
- 2010
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In: Plats, poetik och politik, samtida konst i det offentliga rummet. - 9789178433261 ; , s. 102-107
-
Book chapter (pop. science, debate, etc.)abstract
- Konst på internet för en undangömd tillvaro så länge som vi inte riktar blicken mot de mest framgångsrika objekten som lever i detta nya medium, nämligen spelen. Artikeln placerar in spel och visuella objekt i spel inom ramen för samtida offentlig konst.
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| 22. |
- Hedelind, Mikael, 1981-
(author)
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Realization of Flexible and Reconfigurable Industrial Robot Automation
- 2008
-
Licentiate thesis (other academic/artistic)abstract
- Today’s global market and tough competition between companies requires the development of increasingly productive production systems. Companies, struggling to become more competitive, use different advanced manufacturing technologies, such as industrial robotics. They seek higher productivity, consistent quality, and the removal of ergonomically unsound manual workstations. However, according to the general trends in the manufacturing industry, there is a need to implement production solutions that are flexible enough to handle a business environment exposed to frequent changes in production operations and product designs. The objective of the research presented in this thesis is to analyse how to support the design and implementation of flexible and reconfigurable industrial robot automation.This research is based on three case studies, carried out over a four-year time period. The researcher/author has been a participant in the projects studied. The first case study aimed at developing a flexible robotic working cell, and succeeded. However, although the cell was flexible enough to handle a wide variety of components, there were limitations on how easy it was to reconfigure the cell, i.e. change the operations performed in the cell and the layout of the cell. The second case study investigated how to design robotic working cells so that the cell is easy to reconfigure when there is a need to implement changes. Finally, the third case study focused on software support, with the main focus on enabling the user to rapidly introduce changes into a robotic working cell.As a result of the case studies, enablers for how to realize flexible and reconfigurable robotic working cells have been identified. In addition, the need for software support has been investigated, and a prototype of a supportive software tool has been developed.
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| 23. |
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| 24. |
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| 25. |
- Jonsén, Elisabeth, et al.
(author)
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Psychometric properties of the Swedish version of the Purpose in Life scale
- 2009
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In: Scandinavian Journal of Caring Sciences. - : Blackwell Publishing. - 0283-9318 .- 1471-6712. ; 24:1, s. 41-48
-
Journal article (peer-reviewed)abstract
- The aim of this study was to test the theoretical assumptions beyond the Purpose in Life (PIL) scale, and to elucidate the underlying structure of the Swedish version of the PIL. The PIL, originally created by Crumbaugh and Maholick, is a 20-item scale of the Lickert type with possible scores ranges from 20 to 140, the higher score, the stronger PIL. The analysis was based on 449 participants, 62% of whom were women, from five different samples, ranging from 19 to 103 years old. An exploratory factor analysis restricted to three factors was performed. The factors were labelled meaning in existence, freedom to create meaning in daily life, and will to find meaning in future challenges. These factors reflected the three dimensions described by Frankl. Cronbach's alpha coefficient for the total scale was 0.83 and varied between 0.54 and 0.83 in the three factors. We concluded that the Swedish version of the PIL scale seems to have construct validity and reliability. Our results give support to the fact that the PIL scale captures and confirms the theoretical assumptions of Frankl's existential theory. We consider the PIL scale to be both feasible and appropriate for use in nursing research.
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| 26. |
- Lundgren, Sebastian, et al.
(author)
-
Discovery of KIRREL as a biomarker for prognostic stratification of patients with thin melanoma 11 Medical and Health Sciences 1112 Oncology and Carcinogenesis
- 2019
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In: Biomarker research. - : Springer Science and Business Media LLC. - 2050-7771. ; 7:1
-
Journal article (peer-reviewed)abstract
- There is a great unmet clinical need to identify patients with thin primary cutaneous melanomas (T1, Breslow thickness ≤ 1 mm) who have a high risk for tumour recurrence and death from melanoma. Kin of IRRE-like protein 1 (KIRREL/NEPH1) is expressed in podocytes and involved in glomerular filtration. Screening in the Human Protein Atlas portal revealed a particularly high expression of KIRREL in melanoma, both at the mRNA and protein levels. In this study, we followed up on these findings and examined the prognostic value of KIRREL in a population-based cohort. Immunohistochemical expression of KIRREL was examined in tissue microarrays with a subset of primary tumours and paired lymph node metastases from an original cohort of 268 incident cases of melanoma in the Malmö Diet and Cancer study. KIRREL mRNA expression was examined in 103 melanoma cases in The Cancer Genome Atlas (TCGA). Membranous/cytoplasmic expression of KIRREL was detected in 158/185 (85.4%) primary tumours and 18/19 (94.7%) metastases. High expression of KIRREL was significantly associated with several unfavourable clinicopathological factors. High KIRREL protein expression was an independent factor of reduced recurrence free and melanoma specific survival, particularly in thin melanomas, even outperforming absolute thickness and ulceration (HR = 30.85; 95% CI 1.54-616.36 and HR = 6.32 95% CI 1.19-33.65). High mRNA levels of KIRREL were not significantly associated with survival in TCGA. In conclusion, KIRREL is not only a novel potential diagnostic marker for melanoma, but may also be a useful prognostic biomarker for improved stratification of patients with thin melanoma. These findings may be of high clinical relevance and therefore merit further validation.
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| 27. |
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| 28. |
- Nilsson, Patrik, 1969-, et al.
(author)
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Managing stakeholder requirements in a product modelling system
- 2006
-
In: Computers in industry (Print). - Amsterdam : Elsevier. - 0166-3615 .- 1872-6194. ; 57:2, s. 167-177
-
Journal article (peer-reviewed)abstract
- In order to develop a well-balanced product, it is necessary to consider not only the customers, but also all the other stakeholders throughout the product's life cycle. A holistic view is needed in order to manage all criteria, considering as many perspectives and interests as possible. This paper presents a model that provides a common understanding for stakeholders involved, together with the requirements, functions and sub-systems of the product being developed. The model supports the decision-making process, and supports the designer to balance the interests of different stakeholders and the related functions. This results in a product developed according to all known demands from various stakeholders. This, in turn, will enhance the possibility of success in the market. The model has been applied in an industrial case study.
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| 29. |
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| 30. |
- Nyholm, Tufve, et al.
(author)
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A national approach for automated collection of standardized and population-based radiation therapy data in Sweden
- 2016
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In: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 119:2, s. 344-350
-
Journal article (peer-reviewed)abstract
- Purpose: To develop an infrastructure for structured and automated collection of interoperable radiation therapy (RT) data into a national clinical quality registry. Materials and methods: The present study was initiated in 2012 with the participation of seven of the 15 hospital departments delivering RT in Sweden. A national RT nomenclature and a database for structured unified storage of RT data at each site (Medical Information Quality Archive, MIQA) have been developed. Aggregated data from the MIQA databases are sent to a national RT registry located on the same IT platform (INCA) as the national clinical cancer registries. Results: The suggested naming convention has to date been integrated into the clinical workflow at 12 of 15 sites, and MIQA is installed at six of these. Involvement of the remaining 3/15 RT departments is ongoing, and they are expected to be part of the infrastructure by 2016. RT data collection from ARIA (R), Mosaiq (R), Eclipse (TM), and Oncentra (R) is supported. Manual curation of RT-structure information is needed for approximately 10% of target volumes, but rarely for normal tissue structures, demonstrating a good compliance to the RT nomenclature. Aggregated dose/volume descriptors are calculated based on the information in MIQA and sent to INCA using a dedicated service (MIQA2INCA). Correct linkage of data for each patient to the clinical cancer registries on the INCA platform is assured by the unique Swedish personal identity number. Conclusions: An infrastructure for structured and automated prospective collection of syntactically inter operable RT data into a national clinical quality registry for RT data is under implementation. Future developments include adapting MIQA to other treatment modalities (e.g. proton therapy and brachytherapy) and finding strategies to harmonize structure delineations. How the RT registry should comply with domain-specific ontologies such as the Radiation Oncology Ontology (ROO) is under discussion.
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| 31. |
- Olsson, Rolf, 1969-
(author)
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MANAGING PROJECT UNCERTAINTY BY USING AN ENHANCED RISK MANAGEMENT PROCESS
- 2006
-
Doctoral thesis (other academic/artistic)abstract
- An increasing number of companies are focusing their efforts on project management. Project management is frequently used as an enabler for meeting an uncertain and turbulent environment. Consequently, the overall effectiveness of the project management process is essential for long-term profitability. The aim and final effects of project management are to predict the outcome, i.e. cost, time and quality. However, uncertainty is inherent in the objectives of the project itself, as we use assumptions and expectations in defining and realizing the outcome of the project. A project’s ability to identify and react to uncertainty will influence the outcome of the project. Presently, risk management processes exist in several forms and are often used to manage uncertainty. However, it is frequently argued in academia as well as for the practitioner that risk management does not live up to expected results. The overall objective of this research is to improve the process for managing risks and opportunities within a project organization. The research starts from the single project view, followed by the strategic link to business strategy by including the project portfolio management perspective. Finally, the research focuses on opportunities and the ability of a project to realize them. Thus, the research questions addressed concern how risk is conceived in a theoretical global context and how this would assist in developing a methodology for risk management in an international project organization. They also involve how risk management within a project portfolio could be conducted and its effectiveness measured. Finally, the research questions also address how the management of opportunities could be improved. This research includes the development of four methodologies, based on industrial need. A holistic approach with a systems perspective has been used in order to handle the complexity of the research task. Both empirical and theoretical material has been used for developing the proposed methodologies. The developed methodologies for project risk management and the measures of its effectiveness have been tested and improved over a five-year period within the complete case company. Subsequently, two of them were implemented. The developed methodologies show that the risk management process in a single project does not foster learning and is not directly applicable within a portfolio of projects. Furthermore, the risk management process is not able to address all types of uncertainty. The project manager is a major factor in an effective management of uncertainty. When identifying and managing opportunity, having the ability to create a holistic view, to oversee both customer expectations, and to communicate project related information are important factors. Furthermore, the implementation also showed that it is actually possible, through the consistent use of a risk management process, to develop a cultural behavior within an organization that is much more preventive and proactive than before.
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| 32. |
- Ore, Fredrik, 1978-, et al.
(author)
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Simulation methodology for performance and safety evaluationof human–industrial robot collaboration workstation design
- 2019
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In: International Journal of Intelligent Robotics and Applications. - : Springer. - 2366-5971 .- 2366-598X. ; 3:3, s. 269-282
-
Journal article (peer-reviewed)abstract
- There is a strong interest in the scope of human–industrial robot collaboration (HIRC) in manufacturing industry for greater flexibility and productivity. However, HIRC in manufacturing is still in its infancy; industrial practitioners have many apprehensions and uncertainties concerning the system’s performance and human operators’ safety. Therefore, there is a need for investigations into design processes and methods to make sure the designed HIRC workstations successfully meet design guidelines on system performance, human safety and ergonomics for practical industrial applications. This research proposes a HIRC workstation design process. The novelty of this design process is the methodology to evaluate the HIRC workstation design alternatives by considering both performance and safety characteristics through computer-based simulations. As a proof of concept, the proposed HIRC design process is applied on an industrial manufacturing case from a heavy-vehicle manufacturing company.
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| 33. |
- Raza, Mohsin
(author)
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Developing Process Design Methodology for Investment Cast Thin-Walled Structures
- 2018
-
Doctoral thesis (other academic/artistic)abstract
- Components for engineering systems, such as gas turbines and jet engines operating at high temperature are usually produced in superalloys. The investment casting process is most widely used for manufacturing these components due to the ability of the process to produce parts with complex geometries to close dimensional tolerances. Other processing routes are less advantageous due to high mechanical strength and hardness of these alloys, which make formability and machining difficult even at high temperature. The global requirements for lower fuel consumption and emissions are increasing the demands to lower the weight of cast components in jet engines. The ability to produce components with lower wall thickness will not only help to reduce the cost of production and resource usage but also help to improve the efficiency of engineering systems resulting in lower fuel consumption and reduced emissions of environmentally hazardous gases. However, casting of thin walled components is challenging due to premature solidification in thin sections and long feeding distances often resulting in incomplete filling, cold shuts and shrinkage porosity.The castability of thin-sections is dependent upon selection of appropriate values of casting parameters to achieve favorable conditions for the mould filling and solidification. In foundry environment, fluctuation in these targeted values of casting parameters is common due to semi-automated nature of process. The effects of casting parameters on mould filling and defect formation have been widely reported in the literature, however effect of fluctuations in targeted values of casting parameters resulting from typical variation in the foundry is not well documented. Moreover, the origin of process variation and how to manage them in foundries, especially in relation to thin-walled casting has not been well documented. In this work, the common variations in critical process parameters, originating from foundry practices and equipment are identified. The effect of variations and resulting fluctuation in targeted values of casting parameters on castability of thin-walled castings is evaluated. The casting process is simulated by defining boundary conditions which replicate the foundry conditions and properties of foundry materials in a commercial casting simulation software. The effect of fluctuation of casting parameters on castability of thin-walled castings is established by casting trials as well as simulations and the validity of simulation is evaluated. A methodology to design a casting process is established by proposing methods to minimize the process variation as well as using Design of Experiments (DoE) based simulation work to achieve reliability and repeatability in the process.It is concluded that the mould temperature, casting temperature and pouring rate are common casting parameters affected by the variation originating from equipment and the casting practices. The variation in these parameters strongly effects the castability of thin-walled sections. The significance of these variations is validated by simulation and it is concluded that the validity of simulation is not only strongly dependent upon the foundry specific material data but also depends upon setting up valid boundary conditions according to the equipment and practices used. It is also concluded that by introducing material data and accurate boundary conditions, simulation can be used as tool to facilitate process development in foundries. A systematic implementation of simulations based on DoE and optimization resulted in significant reduction in process development time.The result of this work has been further developed into a process design methodology for investment casting foundries working with casting of thin-walled castings for high temperature applications. The term process design in this work is defined as design and evaluation of gating system as well as identifying optimized values of casting parameters to cast components in foundry.
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| 34. |
- Raza, Mohsin, et al.
(author)
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Effects of process related variations on defect formation in investment cast components
- 2018
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In: Archives of Foundry Engineering. - : Polish Academy of Sciences. - 1897-3310 .- 2299-2944. ; 18:1, s. 103-108
-
Journal article (peer-reviewed)abstract
- Castability of thin-walled castings is sensitive to variation in casting parameters. The variation in casting parameters can lead to undesired casting conditions which result in defect formation. Variation in rejection rate due to casting defect from one batch to other is common problem in foundries and the cause of this variation usually remain unknown due to complexity of the process. In this work, variation in casting parameters resulting from human involvement in the process is investigated. Casting practices of different groups of casting operators were evaluated and resulting variations in casting parameters were discussed. The effect of these variations was evaluated by comparing the rejection statistics for each group. In order to minimize process variation, optimized casting practices were implemented by developing specific process instructions for the operators. The significance of variation in casting parameters in terms of their impact on foundry rejections was evaluated by comparing the number of rejected components before and after implementation of optimized casting practices. It was concluded that variation in casting parameters due to variation in casting practices of different groups has significant impact on casting quality. Variation in mould temperature, melt temperature and pouring rate due to variation in handling time and practice resulted in varying quality of component from one batch to other. By implementing the optimized casting instruction, both quality and process reliability were improved significantly.
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| 35. |
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| 36. |
- Raza, Mohsin, et al.
(author)
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Effects of Process Related Variations on Fillablity Simulation of Thin-Walled IN718 Structures
- 2018
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In: International Journal of metalcasting. - Sweden : Springer Science and Business Media LLC. - 1939-5981 .- 2163-3193. ; 12:3, s. 543-553
-
Journal article (peer-reviewed)abstract
- Simulation tools have improved significantly and are now capable of accurately predicting mould filling behavior. The quality of prediction is highly dependent on material properties and set-up of boundary conditions for the simulation. In this work material properties were measured and casting conditions were analyzed to accurately replicate the casting process in simulation. The sensitivity of the predictions to minor process variations commonly found in foundries was evaluated by comparing simulation and cast samples. The observed discrepancies between simulation and cast samples were evaluated and discussed in terms of their dependency on process variations. It was concluded that the simulation set-up was capable of reasonable predictions and could replicate the asymmetry of the filling however did not accurately predict the absolute value of the unfilled area. It was discovered that asymmetric flow due to variations in the orientation of the casting mould during filling could have greater influence on the predictions than the actual variation in fill time. The quality of simulation is dependent on equipment and techniques used in the foundry as well as the metallurgical model to simulate the process. © 2017, The Author(s).
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| 37. |
- Raza, Mohsin, 1982-
(author)
-
Process development for investment casting of thin-walled components : Manufacturing of light weight components
- 2015
-
Licentiate thesis (other academic/artistic)abstract
- Manufacturing processes are getting more and more complex with increasing demands of advanced and light weight engineering components, especially in aerospace industry. The global requirements on lower fuel consumption and emissions are increasing the demands in lowering weight of cast components. Ability to produce components in lower wall thickness will not only help to reduce the cost of production but also help to improve the efficiency of engineering systems resulting in lower fuel consumption and lesser environmental hazardous emissions. In order to produce thin-walled components, understanding of mechanism behind fluidity as it is effected by casting parameters is very important. Similarly, for complex components study of solidification morphology and its effects on castability is important to understand.The aim of this work was to investigate casting of thin-walled test geometries (less than 2mm) in aero-space grades of alloys. The casting trials were performed to investigate the fluidity as a function of casting parameters and filling system in thin-walled sections. Test geometries with different thickness were cast and evaluated in terms of filled area with respect to casting parameters, ı.e. casting temperature and shell preheat temperature. Different feeding systems were investigated to evaluate effects of filling mode on castability. Similarly for complex components where geometries are very organic in shape, solidification morphology effects the quality of castings. Process parameters, that effect the solidification morphology were identified and evaluated. In order to develop a relation between defect formation and process parameters, solidification behaviour was investigated using simulations and casting trials. Similarly the effect of factors that influence grain structure and flow related defects were studied.It was observed that fluidity is affected by the mode of geometry filling in investment casting process. The filling mode also have different effect on defect formation. A top-gated configuration is strongly affected by casting parameters where as a bottom-gated configuration is more stable and thus fluidity is not significantly affected by variation in casting parameters. Less porosity and flow-related defects were observed in the bottom-gated system as compared to top-gated system. In the study about casting defects as affected by process parameters, it was observed that shell thickness is important to avoid interdendritic shrinkage. It was observed that the increased shell thickness induces a steeper thermal gradient which is essential in order to minimize the width of the mushy zone. It was also observed that a slower cooling rate along with a steeper thermal gradient at the metal-mould interface not only helps to avoid shrinkage porosity but also increases fill-ability in thinner sections.The work presented here is focused on the optimization of process parameters, in order, for instance, to improve castability and reduce the casting defects in investment casting process. The work, however, does not focus on externally influencing the casting conditions or modifying the casting/manufacturing process. The future work towards PhD will be focused on externally improving the casting conditions and investigating other possible route of manufacturing for thin, complex components.
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| 38. |
- Raza, Mohsin, et al.
(author)
-
Simulation based process design approach for manufacturing of light-weight cast components
- 2017
-
Conference paper (peer-reviewed)abstract
- Weight reduction of engineering systems, especially for turbines is desirable due to global requirements for lower fuel consumption and emissions. The resulting design modifications by system manufacturers place demands on foundries to be able to cast thin-walled and complex hot-gas-path components with consistent quality and shorter lead times. The ability to cast components in thinner sections can result in overall weight reduction of turbines. Casting of thin-sections is challenging due to faster solidification and is sensitive to variation in critical process parameters in the foundry. The aim of this work is to develop a framework using design of experiments and simulation to develop a robust casting process as an alternative to costly trial and error that are frequently applied. The Distance based response surface method (RSM) is used to make a Design of experiments (DoE). By using a simulation tool that replicates the process conditions, the test iterations were simulated and regression analysis of the shrinkage and misrun values predicted by the model was performed to determine the effect of casting conditions on defect formation. The optimization of the process conditions was done by adjusting ranges and targets for the response and optimal conditions were proposed for casting.
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| 39. |
- Raza, Mohsin, et al.
(author)
-
The Effect of Shell Thickness, Insulation and Casting Temperature on Defects Formation during Investment Casting of Ni-base Turbine Blades
- 2015
-
In: Archives of Foundry Engineering. - : Walter de Gruyter GmbH. - 1897-3310 .- 2299-2944. ; 15:4, s. 115-123
-
Journal article (peer-reviewed)abstract
- Turbine blades have complex geometries with free form surface. Blades have different thickness at the trailing and leading edges as well as sharp bends at the chord-tip shroud junction and sharp fins at the tip shroud. In investment casting of blades, shrinkage at the tip-shroud and cord junction is a common casting problem. Because of high temperature applications, grain structure is also critical in these castings in order to avoid creep. The aim of this work is to evaluate the effect of different process parameters, such as, shell thickness, insulation and casting temperature on shrinkage porosity and grain size. The test geometry used in this study was a thin-walled air-foil structure which is representative of a typical hot-gas-path rotating turbine component. It was observed that, in thin sections, increased shell thickness helps to increase the feeding distance and thus avoid interdendritic shrinkage. It was also observed that grain size is not significantly affected by shell thickness in thin sections. Slower cooling rate due to the added insulation and steeper thermal gradient at metal mold interface induced by the thicker shell not only helps to avoid shrinkage porosity but also increases fill-ability in thinner sections.
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| 40. |
- Reddy Vemula, Bhanoday
(author)
-
Evaluation of Industrial Robot Mechanical Systems for Applications that Require Human-Robot Collaboration
- 2020
-
Doctoral thesis (other academic/artistic)abstract
- In order to develop robot automation for new market sectors associated with short product lifetimes and frequent production change overs, industrial robots must exhibit a new level of flexibility and versatility. This situation has led to the growing interest in making humans and robots share their working environments and sometimes even allowing direct physical contact between the two in order to make them work cooperatively on the same task by enabling human-industrial robot collaboration (HIRC). In this context, it is very important to evaluate both the performance and the inherent safety characteristics associated with a given industrial robot manipulator system in HIRC workstation during the design and development stages.This necessitates a need to formulate evaluation methods with relevant design metrics and quantitative methods based on simulations, which can support the robot mechanical designer to correlate the task-, and safety- based performance characteristics of industrial robot mechanical system for HIRC applications. The research objective perused in this research aiming to address this need.This research project adopts research methodology based on action-reflection approach in a collaborative research setting between academia and industry. The design knowledge is gained on how to evaluate a specific industrial robot mechanical system design for usability in a specific collaborative application with humans. This is done by carrying out simulation-based evaluation tasks to measure and subsequently analyze the task-, and safety- based performance characteristics of industrial robot mechanical systems. Based on the acquired knowledge, an evaluation methodology with relevant design metrics and simulation modelling approaches is proposed in this research which integrates simulation based design processes of both Human-industrial robot workstation as well as robot mechanical system in order to make a well-grounded assessment on whether the robot mechanical system fulfills the task- and safety-based performance requirements corresponding to a specific collaborative application.
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| 41. |
- Reddy Vemula, Bhanoday, et al.
(author)
-
Human-robot impact model: For safety assessment of collaborative robot design
- 2017
-
In: Proceedings - 2017 IEEE 5th International Symposium on Robotics and Intelligent Sensors, IRIS 2017. - 9781538613429 ; , s. 236-243
-
Conference paper (peer-reviewed)abstract
- In this research, a novel impact simulation model based on compliant contact force (CCF) modelling approach is presented. This model can simulate the physical impact between non-homogeneous and layered elastic bodies representing the robot and human body parts. The proposed CCF model is intended to be used by the robot designers to execute safety evaluation tasks during the design and development of collaborative robot systems. The main theoretical contribution from this CCF impact model is related to the formulations, which can account for the contact behavior due to the non-homogeneous nature of the impacting bodies. The relevance of the proposed impact simulation is evaluated based on a comparative analysis with other available relevant models from the literature as well as with Finite element based simulation model. Finally, the influence of various robot design parameters on the impact severity is analyzed for different impact scenarios by adopting the proposed CCF model.
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| 42. |
- Rösiö, Carin, 1979-, et al.
(author)
-
Agil och rekonfigurerbar produktion : projektmetod och utformning av produktionssystem
- 2020
-
Reports (other academic/artistic)abstract
- För att kunna hantera dagens snabba förändringar är agilitet en färdighet svenska tillverkande företag behöver besitta och kontinuerligt utveckla vidare. Kärnpunkten i att vara en agil verksamhet är att snabbt kunna agera på förändringarpå marknaden eller omgivningen med ett fokus på kundens behov som kräver anpassade snarare än standardiserade produkter.Agilitet inbegriper många olika begrepp som idag cirkulerar kring förmågan att snabbt anpassa sig och förändra sin produktion eller sin organisation till förändringar på marknaden. Relaterade begrepp är flexibilitet, rekonfigurerbarhet och resiliens.Rekonfigurerbarhet innebär att göra det möjligt att lägga till, ta bort och / eller ordna om element/beståndsdelar i produktionssystemet på ett snabbt och kostnadseffektivt sätt som kan resultera i en önskad uppsättning alternativa konfigurationer.Denna handbok är framtagen för att ge ett stöd till tillverkande svensk industri vid utveckling av agila och rekonfigurerbara produktionssystem. Detta innefattar både att använda agila projektmetoder och att skapa agila och rekonfigurerbara produktionssystem.Oavsett om företaget står inför en större förändring av befintliga produktionssystem eller ska utforma något alldeles nytt är handboken användbar. Den är ett stöd både för projektgenomförandet och för hur det faktiska produktionssystemet ska utformas utifrån agila principer. Handboken behandlar således både projektmetod (kap 2) och utformning av ett agilt och rekonfigurerbart produktionssystem(kap 3).
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| 43. |
- Sjögren, Peter, 1986-
(author)
-
Considering Engineering Change Management in Project Realisation : The Case of Offshore Platform Projects
- 2015
-
Licentiate thesis (other academic/artistic)abstract
- Offshore wind converter platforms are complex installations that increase the competitiveness of offshore wind as an energy source. Prior research in the field of offshore platform project execution has focused on early project phases and planning as means to increase project reliability. Later phases such as fabrication, transport and installation have not received the same attention from academia and industry. Projects of this type frequently suffer both large and small deviations. The further projects progress, the more deviations they accumulate. The accumulated deviations have to be resolved in a timely manner so as to avoid impairing the quality and scheduling of an overall project. This research explores the design of converter platforms and the management of engineering change in relation to fabrication, transport and installation in order to increase the overall reliability of projects.Two offshore platform projects in three case studies form the source of empirical data. The first of the three studies considered prior research connected to fabrication and installation of offshore platforms. In the second study, the effect of two different platform designs on the fabrication and installation process was investigated. The third study considered engineering change management as a tool to achieve changeability, and examined its ability to buffer against deviations affecting later project phases i.e. fabrication, transport and installation. The findings revealed that the design’s effects on a project’s outcome are often not the driver of reliability. Rather, it was found that engineering change management is essential to any project to manage the changeable nature of projects. This research also raises concerns as to how much engineering change to allow for and in what project phase. That engineering change, as a tool, should preferably be used sparingly in early phases and as necessary in later phases. The observed engineering change process in the studied projects was chaotic. This research suggests that engineering change can be organised around change carriers. In this way, it is predicted that the processes of change can become more stable and predictable.
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| 44. |
- Sjögren, Peter, et al.
(author)
-
ENGINEERING CHANGE MANAGEMENT IN ENGINEERING-TO-ORDER PROJECTS FROM A MANUFACTURING PERSPECTIVE
- 2014
-
In: 6th Swedish Production Symposium SPS'14.
-
Conference paper (peer-reviewed)abstract
- The purpose of this research was to investigate the engineering change management process in engineering-to-order projects while comparing the same process in traditional manufacturing. A single-case study at a engineering-to-order – engineering review office was performed and results were analysed in conjuction with literature covering the engineering change process in traditional manufacturing. Engineering-to-order projects and tradional manufacturing are different in many ways but share the need for a reliant engineering change process. This study found that engineering change management post-change analysis could benefit future projects in the form of quantifiable lessons learned from previous project’s engineering change data.
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| 45. |
- Sjögren, Peter, et al.
(author)
-
Managing emergent changes: ad hoc teams' praxis and practices
- 2018
-
In: International Journal of Managing Projects in Business. - : EMERALD GROUP PUBLISHING LTD. - 1753-8386 .- 1753-8378. ; 11:4, s. 1086-1104
-
Journal article (peer-reviewed)abstract
- Purpose The purpose of this paper is to explore how emergent changes are handled in research and development (R&D) projects. R&D projects' business potential lies in their exploration of the unknown; conversely, this makes them uncertain endeavours, prone to emergent changes. Design/methodology/approach Uses a single-case-study design, based on a projects-as-practice perspective and a soft systems methodology (SSM) analysis, to map how ad hoc R&D teams handle emergent changes, specifically the solution identification and assessment phase and the implementation plan. An R&D project in the power industry, involving over 250 engineers, was analysed. Findings This paper shows how emergent changes are handled differently from initiated changes during the decision-making phase. The system analysis shows that the most critical factors for managing these changes are: collective reflection between project parties; and including experienced engineers in implementation-plan reviews. Practical implications The results are of relevance both to R&D managers aiming to improve team performance and to general project management. Informal notions of emergent changes can be formalised in the change request process. Weaknesses in the project team's organisation are highlighted, and details of how of how to mitigate these are provided. Originality/value Combines engineering-design and project-management research on emergent changes, adding to the former regarding people-organisational and strategic issues. Furthers understanding of the projects-as-practice approach and emergent change (deviations) handling by ad hoc teams in a project environment. SSM has not previously been used to explore aspects of projects-as-practice, and this is a novel way of adding to the body of knowledge on project praxis and practise.
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| 46. |
- Sjögren, Peter, et al.
(author)
-
MANUFACTURING ASPECTS OF OFFSHORE FABRICATION AND INSTALLATION
- 2014
-
In: International Journal of Maritime Engineering. - 1479-8751 .- 1740-0716. ; 156, s. 277-284
-
Journal article (peer-reviewed)abstract
- The research presented in this paper aim at identifying research commonalities between shipbuilding, offshore fabrication practices and manufacturing. As part of an exploratory effort a literature review and a case study of two offshore structures projects were performed. Research concerning shipbuilding and offshore fabrication, together with literature from other industries in construction, larger engineering projects and traditional manufacturing was reviewed. The two offshore structures projects were analyzed by means of interviews and complemented by direct observations and document reviews. The study concludes that there are gaps in the research concerned with holistic perspectives on the fabrication and installation phases of shipbuilding and offshore projects. The number of actors involved in any project of this magnitude increase barriers and communication interfaces. The dynamic nature of these types of projects was also observed and the changeability should always be a accounted factor when dealing with projects of this sort. The interviews held as part of the verification of observed phenomena in literature was limited to two projects and a single company and actors perceptions. However the collected data served well in being complementary to the literature review. It could be the task of academia to patch the gaps for overall project success, in the cases where single industry actors simply cannot see the benefit or do not have the recourses to fill them themselves. This study combines findings from traditional manufacturing industries, shipbuilding, offshore structures fabrication and large engineering projects in general.
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| 47. |
- Sjögren, Peter, et al.
(author)
-
Opportunity discovery in initiated and emergent change requests
-
Other publication (other academic/artistic)abstract
- In this research, we analyze practitioner practices and praxes associated with discovering and exploiting opportunities in project-based change requests. Change requests are the aggregation of engineering changes and are considered in a redesign process. Raising a change request initiates the formation of an ad hoc team to manage it. A single case study design was employed using change request records and practitioner interviews from an engineering project. Additionally, the collected data was used to analyze discovered and exploited opportunities from a projects-as-practice perspective. Prior research on change requests has shown that practitioners often view changes in a risk-averse manner. However, a risk-averse mindset does not encompass opportunities. Our findings emphasize the importance of the informal structure of ad hoc teams, as opposed to formal structures, to aid in opportunity discovery. The informal structure enables cross-hierarchal discussions among team members and draws on the proven experience of the team members. Finally, the dynamic, dual structure of ad hoc teams (engineering and on-site teams) is an essential part of opportunity discovery. Adding to the existing knowledge in the field of engineering change management, we present a framework that supports practitioners in identifying how to turn engineering changes into successful opportunities.
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| 48. |
- Sjögren, Peter, et al.
(author)
-
Opportunity discovery in initiated and emergent change requests
- 2019
-
In: Design Science. - : Cambridge University Press (CUP). - 2053-4701. ; 5
-
Journal article (peer-reviewed)abstract
- When a change request is raised in an engineering project an ad hoc team often forms to manage the request. Prior research shows that practitioners often view engineering changes in a risk-averse manner. As a project progresses the cost of changes increases. Therefore, avoiding changes is reasonable. However, a risk-averse perspective fails to recognize that changes might harbor discoverable and exploitable opportunities. In this research, we investigated how practitioners of ad hoc teams used practices and praxes aimed at discovering and exploiting opportunities in engineering change requests. A single case study design was employed using change request records and practitioner interviews from an engineering project. 87 engineering change requests were analyzed with regards to change triggers, time-to-decision and rejection rate. In total, 25 opportunities were discovered and then 17 exploited. Three practices and six praxes were identified, used by practitioners to discover and exploit opportunities. Our findings emphasize the importance of the informal structure of ad hoc teams, to aid in opportunity discovery. The informal structure enables cross-hierarchal discussions and draws on the proven experience of the team members. Thus, this research guides project managers and presumptive ad hoc teams in turning engineering changes into successful opportunities.
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| 49. |
- Sjögren, Peter, et al.
(author)
-
SEMI-SUBMERSIBLE GRAVITY BASED HYBRID STRUCTURE – AN ALTERNATIVE TO JACKET AND TOPSIDE PLATFORMS
- 2014
-
In: Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, vol. 8B, 2014. - 9780791845516
-
Conference paper (peer-reviewed)abstract
- The aim of this research is to present the result from a case study comparing a semi-submersible gravity based hybrid structure and a jacket topside structure for two offshore wind farm converter station projects. The cases are analyzed from a transportation and installation perspective. Converter stations enable the conversion from alternating to direct current, more efficiently bringing generated wind energy to shore. Out of the project process phases e.g. planning, engineering, fabrication, transport, installation and commissioning; transportation and installation are two of the most demanding during offshore platform projects. The weight and size of an offshore platform require specialized equipment, vessels and marine contractors’ expertise to be transported and installed. The risks associated with transportation and installation (T&I) operations are related to health, safety and environment, and T&I operations are also sensitive to any disturbance e.g. accidents and delays. Many interdependencies between disciplines in the project execution process may result in consequential and immediate impact, should an activity not follow the plan and thus the risk of cost overruns increases. In an attempt to circumvent risks related to heavy lifts offshore and consequently mitigate the corresponding risks, a new platform concept has been developed a Norwegian EPC –company and a Swiss converter station manufacturer, a semi-submersible gravity based hybrid, SSGBH. The subjects presented in this paper include the general principles of the SSGBH concept and in what way risk associated with T&I operations are reduced. This paper present the platform concepts, data gathered from interviews, archival data and direct observations. Their pros and cons are presented in an objective way, while concluding that platform concepts of this kind are and should be highly customized, as should the concept selection.
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| 50. |
- Sjögren, Peter, et al.
(author)
-
Structuring the engineering change management process around change carriers
- 2015
-
In: IEEE International Conference on Industrial Engineering and Engineering Management. - 9781467380669 ; , s. 416-420
-
Conference paper (peer-reviewed)abstract
- Prior research in the field of offshore platform project execution has mainly focused on early project phases and planning, as a means to increase project reliability for offshore installations. Later phases, however, as fabrication, transport and installation have not been given the same attention. Projects of this kind frequently suffer both large and small deviations and as projects progress deviations accumulate. Deviations then have to be resolved in a timely manner not to impair quality and scheduling of an overall project. Empirical data was gathered from two offshore platform projects in the form of archival data, observations and interviews. The findings revealed that engineering change, as a tool, should preferably be used sparingly in early phases and as necessary in later phases. This research also suggests that engineering change can be organized around change carriers. In this way, it is predicted that the processes of change can become more stable and predictable.
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