| 1. |
- Cedergren, Stefan, 1982, et al.
(författare)
-
The effects of grain size and feed rate on notch wear and burr formation in wrought Alloy 718
- 2013
-
Ingår i: International Journal of Advanced Manufacturing Technology. - : Springer Science and Business Media LLC. - 0268-3768 .- 1433-3015. ; 67:5-8, s. 1501-1507
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of two different workpiece material grain sizes, 16 and 127 μm, on the depth-of-cut notch wear, chip morphology, and burr formation was studied in a turning operation. A material from the same batch of wrought superalloy Alloy 718 was heat-treated to achieve the two microstructures. The machining was performed at two feed rates, 0.1 and 0.2 mm/revolution. Uncoated cemented carbide tools were used. Both grain size and feed rate were found to influence the chip morphology and the sideflow which were also associated with both the notch wear and the burr formation. The effect of the grain size on the notch wear was larger than that of the feed rate under the tested conditions, with larger grains being more detrimental than smaller ones.
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| 2. |
- Bejjani, Roland, et al.
(författare)
-
Variations in the Surface Integrity of Ti-6Al-4V by Combinations of Additive and Subtractive Manufacturing Processes
- 2020
-
Ingår i: Materials. - : MDPI. - 1996-1944. ; 13:8, s. 1-24
-
Tidskriftsartikel (refereegranskat)abstract
- Additive manufacturing (AM) has recently been accorded considerable interest by manufacturers. Many manufacturing industries, amongst others in the aerospace sector, are already using AM parts or are investing in such manufacturing methods. Important material properties, such as microstructures, residual stress, and surface topography, can be affected by AM processes. In addition, a subtractive manufacturing (SM) process, such as machining, is required for finishing certain parts when accurate tolerances are required. This finish machining will subsequently affect the surface integrity and topography of the material. In this research work, we focused on the surface integrity of Ti-6Al-4V parts manufactured using three different types of AM and finished using an SM step. The aim of this study was to gain an understanding on how each process affects the resulting surface integrity of the material. It was found that each AM process affects the materials’ properties differently and that clear differences exist compared to a reference material manufactured using conventional methods. The newly generated surface was investigated after the SM step and each combination of AM/SM resulted in differences in surface integrity. It was found that different AM processes result in different microstructures which in turn affect surface integrity after the SM process.
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| 3. |
- Cedergren, Stefan
(författare)
-
A Conceptual Evaluation Framework for Performance Measurements within Industrial Product Development
- 2009
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Konferensbidrag (refereegranskat)abstract
- The ability to deliver streams of new products to the market is more important than ever before. Still, no generally accepted performance measurement framework for product development exists. This paper outlines a performance measurement evaluation matrix, based on extensive qualitative research within large organizations developing industrial products in Sweden, that enable managers to assess what is and what is not measured in the product development process. This is important in order to continuously keep the measurement system updated according to the current needs of the organization.
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| 4. |
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| 5. |
- Cedergren, Stefan, et al.
(författare)
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A Performance Evaluation Framework for Innovation a chapter in Innovation in Business and Enterprise: Technologies and Frameworks
- 2010
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Ingår i: Innovation in Business and Enterprise. - : IGI Global. - 9781615206438 ; , s. 135-149
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter presents a framework for a conceptual evaluation of the performance of industrial product innovation activities. The framework promotes a holistic view of performance by considering three categories of activities: Planning, Implementation, and Sales and Delivery. Successful performance evaluation comes from acknowledging the fact that there are different objectives for each of the three activity categories. Moreover, performance may be expressed as a function of the performance of the Planning, the Implementation, and the Sales and Delivery activities. In this chapter the results of research involving seven large companies in Sweden, with the objective of improving the understanding of what is required to be successful when developing complex industrial products, are presented. Key factors for success as well as some general conclusions are discussed.
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| 6. |
- Cedergren, Stefan, et al.
(författare)
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A road map for future research on industrial product-service systems (IPS2) : a systematic review
- 2012
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Ingår i: The Philosopher's Stone for Sustainability. - Berlin, Heidelberg : Encyclopedia of Global Archaeology/Springer Verlag. - 9783642328466 - 9783642328473 ; , s. 185-190
-
Konferensbidrag (refereegranskat)abstract
- There is an ongoing trend to expand traditional offerings of selling goods towards providing value through services to customers. In academia the term Industrial Product-Service Systems (IPS2) describes this phenomenon. Although many articles have been published on IPS2 a systematic review is lacking. This paper presents a systematic review of the IPS2 domain. Five themes characterizing IPS2 are revealed: delivery, processes, value creation networks, knowledge management, and business models. IPS2 is concluded to be both a young and distributed field of research, with a scope that needs to expand in terms of the themes covered and number of empirical studies
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| 7. |
- Cedergren, Stefan, et al.
(författare)
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Analysis of the industrial product-service systems (IPS2) literature : A systematic review
- 2012
-
Ingår i: IEEE 6th International Conference on Management of Innovation and Technology, ICMIT 2012. - Piscataway, NJ : IEEE Communications Society. - 9781467301084 ; , s. 733-740
-
Konferensbidrag (refereegranskat)abstract
- Successful industrial goods-delivering companies are always looking for ways to develop and grow their business. A strong present trend is to expand the traditionally tangible offering by integrating intangible offerings i.e. services. In academia the term industrial product-service systems (IPS2) are being used to describe this paradigm shift. However, a systematic review of the IPS2 literature is lacking. In this paper publications regarding IPS2 are systematically reviewed. The result of our review has been categorized under five themes that we found characterizes IPS2: delivery, processes, value creation networks, knowledge management, and business models. Based on our findings a discussion is made and future research directions are identified
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| 8. |
- Cedergren, Stefan, et al.
(författare)
-
Challenges with Evaluating Performance in Product Development
- 2010. - 8
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Ingår i: 17TH INTERNATIONAL PRODUCT DEVELOPMENT MANAGEMENT CONFERENCE. - Murcia, Spain.
-
Konferensbidrag (refereegranskat)abstract
- The purpose of this paper is to from a managerial perspective investigate performance evaluation practices in a product development context. The focus is on exploring how managers perceive and evaluate performance in a software-intensive product development context. The research approach pursued in this research consist of a literature review combined with focused group interviews and exploratory multiple case studies. Moreover, a number of seminars have been held to discuss the findings both in academia and in practice. The result of this research indicates that product development managers are dissatisfied with their current way of evaluating performance. Performance measurements and the perception of performance are focused on cost, time and quality, i.e. what is easily measurable and not necessarily what is important. The dimensions of value creations and learning are missing. It is argued that manager perception of performance is affected by how it is measured, hence limiting the scope of the performance criteria. Thus, a change in the way managers perceive performance is necessary before there can be any change in the way performance is evaluated. Managers within product development that are dissatisfied with their performance measurement system should focus on how the organization perceive performance. By developing relevant performance criteria the first step in developing an effective performance evaluation system is made.
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| 9. |
- Cedergren, Stefan, et al.
(författare)
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Evaluating performance in the development of software-intensive products
- 2014
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Ingår i: Information and Software Technology. - : Elsevier BV. - 0950-5849 .- 1873-6025. ; 56:5, s. 516-526
-
Tidskriftsartikel (refereegranskat)abstract
- Context: Organizational performance measurements in software product development have received a lot of attention in the literature. Still, there is a general discontent regarding the way performance is evaluated in practice, with few studies really focusing on why this is the case. In this paper research focusing on the context of developing software-intensive products in large established multi-national organizations is reported on. Objective: The purpose of this research is to investigate performance measurement practices related to software product development activities. More specifically, focus is on exploring how managers engaged in software product development activities perceive and evaluate performance in large organizations from a managerial perspective. Method: The research approach pursued in this research consist of exploratory multiple case studies. Data is collected mainly through 54 interviews in five case studies in large international organizations developing software-intensive products in Sweden. Focused group interviews with senior managers from eight companies have also been used in the data collection. Results: The results of this research indicate that managers within software product development in general are dissatisfied with their current way of evaluating performance. Performance measurements and the perception of performance are today focused on cost, time, and quality, i.e. what is easily measurable and not necessarily what is important. The dimensions of value creation and learning are missing. Moreover, measurements tend to be result oriented, rather than process oriented, making it difficult to integrate these measurements in the management practices. Conclusion: Managers that are dissatisfied with their performance measurement system and want to improve the current situation should not start by focusing on the current measurements directly; instead they should focus on how the organization perceives performance and how important performance criteria are being developed. By developing relevant performance criteria the first step in developing an effective performance measurement system is made. Moreover, it is concluded that manager's perception of performance is affected by the currently used measurements, hence limiting the scope of the performance criteria. Thus, a change in the way managers perceive performance is necessary before there can be any changes in the way performance is evaluated.
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| 10. |
- Cedergren, Stefan, et al.
(författare)
-
Evaluation of performance in a product development context
- 2010. - 4
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Ingår i: Business Horizons. - : Elsevier. - 0007-6813 .- 1873-6068. ; 53:4, s. 359-369
-
Tidskriftsartikel (refereegranskat)abstract
- In today's competitive environment, the need is greater than ever to deploy product development investments more effectively. To assist managers, we have developed two conceptual tools to support the evaluation of performance in product development. The Performance Measurement Evaluation Matrix (PMEX) helps managers evaluate performance measurement systems they currently use, in order to identify areas requiring improvement. Results from using the PMEX indicate that it is common to associate performance measurements with the efficiency aspects of time, cost, and quality, without monitoring the value created. Performance is largely perceived by managers in terms of time, cost, and quality of the activities in the later phases of the development process. We contend that an effective performance measurement system is based on performance criteria, and then derives measurements based on these. It is argued that there should be a change in the perception of performance, before performance evaluation systems can be improved. The Product Development Organizational Performance Model (PDOPM) assists in developing the perception of performance by relating uncertainty, efficiency, and effectiveness at three generic activity levels within the product development function. The use of our tools provides an improved perception of performance and its measurement, thus enabling improvements to the evaluation of performance.
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| 11. |
- Cedergren, Stefan, et al.
(författare)
-
Improving Traceability by Focusing on Value during Development
- 2011
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Ingår i: 1st International Workshop on Value-Based Software Traceability (VALSOT 2011).
-
Konferensbidrag (refereegranskat)abstract
- Product delivering companies invest resources in software development activities in order to create value. Still, when performance in software development is to be measured, focus easily turns to time, cost, and quality in the later stages of the development process. Time, cost, and quality are important dimensions of performance but they are not revealing the complete picture. Missing is the value perspective. This paper outlines a method for how customer value can be used to evaluate performance and improve traceability during the development of a new product. The first step in the method is to value each requirement in the development project according to their perceived customer value. Hence, the value propagation can be monitored as the activities related the requirements are completed during the development. This information can then be used in order to improve traceability by visualizing the value propagation and performance during the development. The paper is concluded with outlining four key needs for future research.
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| 12. |
- Cedergren, Stefan, 1982, et al.
(författare)
-
Influence of deformed surface layer when machining wrought alloy 718 in an annealed and in a pre-strained condition
- 2014
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Ingår i: 8th International Symposium on Superalloy 718 and Derivatives 2014; Pittsburgh; United States; 28 September 2014 through 1 October 2014. - Hoboken, NJ, USA : John Wiley & Sons, Inc.. - 9781634396424 ; , s. 263-271
-
Konferensbidrag (refereegranskat)abstract
- Superalloys are difficult to cut, mainly due to their preserved strength at elevated temperatures and their exceptional work hardening, where the latter results in a deformed layer on the machined surface. The thickness and degree of deformation of this layer depends on several parameters, such as cutting speed, uncut chip thickness, tool material and edge geometry. This layer enters the cutting zone of subsequent revolutions in turning or in milling. Under certain circumstances, as when the uncut chip thickness is small, all deformation at subsequent machining takes place within the deformed layer. The same phenomenon may occur at the outer edge of the cutting zone where the unrestricted material flow leads to burr formation. The deformed layer at the outer edge is suggested as the cause for notch wear often found when machining Superalloys. In this paper the effect of deformed layer on machining is examined through controlled experiments on the material in to different states of strain; in the annealed state without any remaining strain and with a substantial amount introduced by tensile straining. The results showed that cutting forces were reduced when pre-straining the material. Tool wear was similar in both materials, with large scatter due to built-up edge formation.
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| 13. |
- Cedergren, Stefan, 1982
(författare)
-
Influence of Material Variations on Machinability - Machining Difficult-to-Machine Alloys
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study is to investigate the effect of work material variations on machinability. Improved knowledge in this respect supports the development of sustainable production both from resource and economical points of view.The properties of work materials vary greatly depending on how they were manufactured. Castings generally have coarse microstructure compared to wrought material, where the added thermo-mechanical processing steps in the latter produce finer microstructure. Local within-part variations in microstructure are found in both castings and wrought material. In cast material this varies due to factors such as undercooling and cooling rate. In wrought material local variations in process parameters, such as deformation and temperature produce different microstructures.Within-process variations during machining also exist, where surfaces deformed during cutting are left to subsequent cuts. The same occurs when machining sheet metal, where degree of deformation also may vary due to local variations in strain. In this work differences in both microstructure and deformation has been investigated for three work materials; nickel-iron based Alloy 718, titanium alloy Ti-6Al-4V and the stainless steel 316L. It was found that coarse microstructures result in anisotropic chip formation, where chips had a non-periodic serrated appearance in both Alloy 718 and Ti-6Al-4V. Both alloys are known to produce continuous chips at low feed rates and cutting speeds, with a transition to serrated chips as these parameters are increased, due to instability in the cutting process. The serrations due to this instability show a more periodic appearance, clearly distinguishable to the serrations due to anisotropy.In Alloy 718 coarse microstructure was also found to produce large burrs, that were continuously built-up during machining, as well as increase notch wear at the depth-of-cut on the cutting tool. In Ti-6Al-4V the anisotropic chip formation behavior found in coarse microstructure was connected to orientations of alpha colonies, i.e. where some orientations produce highly localized deformation and others were homogeneously deformed at all feed rates and speeds investigated. Chip breakability was found to increase with size of alpha colonies, aided by the colonies that had highly localized deformation. The influence of the less periodic serrations found in coarse microstructure was also found to produce vibrations over a wider cutting speed range compared to the periodic serrations in finer microstructures.In both Alloy 718 and stainless steel 316L cutting forces were reduced when the work material had been deformed prior to machining, compared to annealed material.
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| 14. |
- Cedergren, Stefan, 1982
(författare)
-
Influence of Microstructure on Chip Formation - Machining Aero Engine Alloys
- 2012
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aero engine materials such as nickel-iron and titanium based alloys are known to be very difficult to machine. They are also known to produce shear-localized chips; a type of chip which is associated with both an increase of the tool wear and the vibration levels during machining. Robust machining operations are crucial for maintaining high productivity in the machining shop and variations in the actual work material, e.g. between batches or when the material supplier is changed, are known causes for unwanted disturbances. It goes without saying that a deeper understanding of how the work material microstructure interacts with the machining operation will lead to more robust processes. The aim of this work was to increase the understanding of how the microstructure of work material influences shear-localized chip formation. This was studied through transverse and orthogonal turning in two alloys, the superalloy Alloy 718 and the titanium alloy Ti-6Al-4V, for both of which the microstructure was varied by means of heat treatment. It was found that if the microstructures were finer than the uncut chip thickness, the machining behaviour was isotropic with a gradual increase of the shear-localization in chips when the cutting speed was increased in Alloy 718, and when feed rate was increased in Ti-6Al-4V. However, when the size of the microstructural constituents was increased through heat treatments and to be in the same order of magnitude as the chip thickness, anisotropic effects were found. The result was serrated chips at all cutting speeds in the case of Alloy 718, due to anisotropic deformation of grains at low speeds and with an increased influence of shear localization at higher speeds. The amount of shear localization was found to vary with the crystallographic orientation. In Ti-6Al-4V the orientation of the lamellar structure in the coarse Widmanstätten microstructure type affected the shear localization and this anisotropy could explain the presence of large lamellae in chips even at low feed rate.
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| 15. |
- Cedergren, Stefan, 1982, et al.
(författare)
-
Influence of work material microstructure on vibrations when machining cast Ti-6Al-4V
- 2016
-
Ingår i: The International Journal of Advanced Manufacturing Technology. - London : Springer. - 0268-3768 .- 1433-3015. ; 84:9-12, s. 2277-2291
-
Tidskriftsartikel (refereegranskat)abstract
- Titanium alloys are known to produce shear-localized chips during machining, resulting in cyclic variations in cutting forces which in turn could cause severe problems with vibrations. However, at low cutting speeds and feed rates, continuous chips are formed, with an increase in both parameters favoring the transition to shear-localized chips. This transition is affected by work material microstructure, where a coarse microstructure gives anisotropic effects, e.g., when the size of alpha colonies is on the same order of magnitude as the primary cutting zone. The change in chip morphology with an increase in cutting parameters will then be dependent on the orientation of alpha colonies within the cutting zone. The microstructure of work material can show large variations depending on product form, e.g., cast, wrought, or sheet material, thus affecting whether the chip formation is isotropic or anisotropic. Other sources of variations also exist that can be found within the same component, such as segregation of alloying elements and differences in thermo-mechanical history during processing due to geometry. In this study, the interaction between work material microstructure, process parameters, and the machining system’s structural characteristics is studied. The aim is to further increase the knowledge about vibrations during machining of titanium and the role of microstructure and machining system properties. Different microstructures were produced by adding boron to cast Ti-6Al-4V material, where the resulting colony sizes gave both isotropic and anisotropic chip formation within the chosen cutting data range. The machining systems dynamic properties were varied by using different tool overhangs, thereby simulating different configurations of natural frequencies and stiffness. The results show the influence of both microstructure and machining system’s structural characteristics on the dynamic response of the system for different process parameters. This information can be used to increase robustness of machining operations taking into consideration this three-way relationship.
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| 16. |
- Cedergren, Stefan, et al.
(författare)
-
Machinability of cast titanium alloy Ti-6Al-4V with addition of boron
- 2020
-
Ingår i: MATEC Web of Conferences. - : EDP Sciences. - 2261-236X. ; 321
-
Tidskriftsartikel (refereegranskat)abstract
- Cast titanium products generally have coarser microstructures compared to wrought, which explains their limited mechanical properties. However, instead of additional thermo-mechanical processing steps, as in the case of wrought components, the microstructure of castings can be refined by additions of boron. This enhances yield strength, tensile strength and ductility. In order to investigate the influence on machining of this microstructural refinement, cutting tests were performed in three different Ti-6Al-4V castings, having 0, 0.06 and 0.11 wt.% boron. Five machinability criteria were studied; cutting force, chip breakability, burr formation, surface roughness and tool wear. The results show anisotropic deformation behavior in chips when alpha colony size is on the same order of magnitude as the primary deformation zone, or larger. There was little or no influence on cutting forces and burr formation, however chip breakability and tool life was reduced when boron was added. Surface roughness showed a more complex behavior where 0.06 wt.% boron resulted in rougher surfaces compared to the other compositions at low feed rate.
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| 17. |
- Cedergren, Stefan, et al.
(författare)
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Making the Important Measurable
- 2011
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Ingår i: International Association for Management of Technology IAMOT 2011 Proceedings. - Miami Beach, USA.
-
Konferensbidrag (refereegranskat)abstract
- Performance measurements related to product development typically focuses on what is easy to quantify and not necessarily what is important to measure. This research uses a case study approach to test a new model for designing performance indicators (DPI) based on what is important for a specific organization developing new products. The foundation for an effective performance measurement system is that the performance measurements are derived from relevant performance criteria and objectives. The proposed DPI method is therefore based on three consecutive steps. The first step is to decide what performance objectives are needed to be fulfilled in order to realize the pursued strategy. This step is followed by the identification of performance criteria / success factors that will contribute to the realization of the performance objectives. Performance criteria are typically related to what needs to be achieved in order to fulfill the objectives while success factors focus more on how they are to be fulfilled. Based on the most important performance criteria /success factors the supporting performance indicators can be derived from the literature or by using the performance measure record sheet. The performance allocation tracker is developed as a result of applying the DPI method in a real case and it is an indicator of the performance of the studied development project. The properties of the indicators resulting from using the DPI method include similar characteristics as leading indicators of performance. It is concluded that by focusing on performance criteria and success factors in the development of performance indicators, leading indicators of performance is derived.
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| 18. |
- Cedergren, Stefan, 1982, et al.
(författare)
-
On the Influence of Work Material Microstructure on Chip Formation, Cutting Forces and Acoustic Emission when Machining Ti-6Al-4V
- 2013
-
Ingår i: Procedia CIRP. - : Elsevier BV. - 2212-8271. ; 12, s. 55-60
-
Konferensbidrag (refereegranskat)abstract
- The influence of heat treatment of work material on chip formation, when machining Ti-6Al-4V, was studied through microstructural investigation of chips, as well as response on cutting forces and acoustic emission. Three different microstructures were investigated; equiaxed, bimodal and Widmanstätten. It is well known that machining of titanium produces shear localized chips at all industrially practical cutting speeds and feed rates, however there is also a transition from aperiodic to periodic sawtooth chip formation. The feed rate was varied at constant cutting speed to study this transition from aperiodic to periodic saw-tooth chips in the three microstructures. Face turning cutting tests were used when sensor signals were collected. The results from this investigation stress the importance to consider work material microstructure when studying the chip formation process, and its impact on cutting forces and acoustic emission, when machining Ti-6Al-4V.
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| 19. |
- Cedergren, Stefan
(författare)
-
Performance Evaluation in an Industrial Product Development Context
- 2009
-
Konferensbidrag (refereegranskat)abstract
- In today’s turbulent and competitive environment the need for deploying product development investments more efficiently and effectively is stronger than ever. To assist managers in this context, two conceptual tools to support the performance evaluation process in a product development context have been developed, based on extensive exploratory case studies. Results indicate that it is common to associate performance measures with time, cost and quality; missing is the monitoring of the value created. It is argued that there needs to be a change in the perception of performance, before there can be any changes in the performance evaluation system.
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| 20. |
- Cedergren, Stefan, 1978-
(författare)
-
Performance in Product Development - The Case of Complex Products
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This research addresses the concept of performance in the development of complex products. More specifically, its aim is to study how performance is perceived and measured within large global companies, and how performance measurement systems can be designed in a systematic way. The exploratory results regard how performance is currently perceived and measured. It is argued that performance measurements are focused on the later stages of the development of complex products, thus making it difficult to perform changes during the development. The focus is on lagging rather than leading indicators of performance, hence it is concluded that focus is on reporting the result rather than the causes of the result. In line with these findings is the weak link between what managers perceive as success factors and what is measured, the perception of performance being influenced by what is measured, rather than the reverse. The prescriptive results focus on the development of models and frameworks to be used during the development of complex products. A general method for developing performance indicators is presented. The concept of Products in Development is proposed, this making it possible to monitor how value is created during the development of a product. Both these models aim at complementing the currently used performance measurement system in order to support effective and efficient development of complex products. The method used in this research is mainly focused around the collection of qualitative data through a focused group interview, multiple case studies,and industrial reference-group seminars. A survey has also been used to complement the qualitative with quantitative data. The use of various research methods has made it possible to triangulate the data, thus strengthening the validity of the findings.
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| 21. |
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| 22. |
- Cedergren, Stefan, et al.
(författare)
-
PMEX — A PERFORMANCE MEASUREMENT EVALUATION MATRIX FOR THE DEVELOPMENT OF INDUSTRIAL SOFTWARE-INTENSIVE PRODUCTS
- 2011. - 6
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Ingår i: International Journal of Innovation and Technology Management (IJITM). - : World Scientific Publishing. ; 8:1, s. 55-76
-
Tidskriftsartikel (refereegranskat)abstract
- The ability to measure performance is both fundamental to and critical in successful product development. Previous research has focused on adding new measurements, not on evaluating those currently used. The performance measurement evaluation matrix (PMEX) is a tool to evaluate the performance-measurement system based on success factors in the development of software-intensive products. Three case studies have been conducted to test the PMEX and the results indicate that the PMEX enables managers to determine explicitly what is and what is not measured. Time, cost, and quality seem to be the focus of the performance measurements while technology and planning activities are absent.
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| 23. |
- Cedergren, Stefan, et al.
(författare)
-
Products in Development: Using Requirements to Determine the Value of Activities in a Development Project
- 2012
-
Konferensbidrag (refereegranskat)abstract
- Product delivering companies invest resources in software development activities in order to create value. Still, when performance in software development is to be measured, focus easily turns to time, cost, and quality in the later stages of the development process. Time, cost, and quality are important dimensions of performance but they are not revealing the complete picture. Missing is the value perspective. This paper outlines a method for how customer value can be used to evaluate performance and improve decision making during the development of a new product. The first step in the method is to value each requirement in the development project according to their perceived customer value. Hence, the value propagation can be monitored as the activities related the requirements are completed during the development. This information can then be used in order to decide on changed priorities through an understanding of the value propagation and performance during the development.
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| 24. |
- Cedergren, Stefan, et al.
(författare)
-
Success factors and performance measurements : a missing link in product development?
- 2012
-
Konferensbidrag (refereegranskat)abstract
- Performance measurements are important for managing operation and supply chain activities. The literature within performance measurement and success factors in innovation and product development is vast, but with little cross-fertilization. In industry there is a clear consensus among manager’s that their measurements are not covering what is important to be successful. One explanation for this, as argued for in this paper, might be that there is a weak connection between what is considered to be important (a success factor) and what is actually measured by the performance measurement system in product development. In this paper the findings from a survey among large manufacturing companies in Sweden is presented. The paper is concluded with an analysis and discussion regarding why success factors are not represented in the performance measurement system and recommendations for future research.
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| 25. |
- Cedergren, Stefan, et al.
(författare)
-
Towards Integrating Perceived Customer Value in the Evaluation of Performance in Product Development
- 2010. - 7
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Ingår i: PICMET 2010. - : IEEE. - 9781890843229
-
Konferensbidrag (refereegranskat)abstract
- Product delivering companies invest resources in product development activities in order to create value. Still, when performance in product development is to be evaluated, time, cost, and quality are in focus, especially in the later stages of the development when it is expensive and difficult to make any changes. Time, cost, and quality are important dimensions of performance but they are not revealing the complete picture. Missing is the value perspective. This paper outlines a method for how perceived customer value can be used to evaluate performance in product development and describes how it is verified through a case study. By using the perceived customer value of requirements, the value propagation throughout the development is possible to monitor based on both market and scope changes. In addition, a measure of productivity can be calculated by relating the perceived value to the spent effort. This information is used in order to visualize the value propagation and performance during the development. Hence, through this method it is possible to evaluate the productivity of activities from initial ideas to a final product. The paper is concluded with a discussion of managerial implications and how this method contributes to theory.
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| 26. |
- Cedergren, Stefan, et al.
(författare)
-
What is Performance in Complex Product Development?
- 2008
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Ingår i: Proceedings of the R&D Management Conference. 2008.
-
Konferensbidrag (refereegranskat)abstract
- The process of developing new products is one of the key business processes in a company, especially technology intensive ones. In order to continuously improve this capability of developing new products it is important to be able to measure the performance in the product development process. The dilemma though is that there are no good performance measurements available within complex product development. One reason, as argued in presented research may be the lack of a holistic perception of performance within the development process. Data from a five case explorative study including 49 semi-structured open interviews regarding performance within complex product development is presented and analyzed. The results clearly indicate a need for further development of the perception of performance by managers and decision makers within the process of developing complex products. To meet this need, a Product Development Organizational Performance Model (PDOPM) is proposed, consisting of three generic levels of activities: Product strategy, Project management, and Product activities. These generic activities are modelled in accordance with the IDEF0 making it possible to conceptually reason about uncertainty, effectiveness, and efficiency at each activity level. Further, the term product development efficacy is introduced to describe the capability of identifying or creating a market opportunity and being able to develop and deliver a product fulfilling exactly what was identified as the market opportunity. High performance in product development is achieved when there is efficacy throughout the complete product development portfolio.
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| 27. |
- Duhan, Alice, 1986-
(författare)
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Les langues du roman translingue : Une étude de Nancy Huston, Vassilis Alexakis et Andreï Makine
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Although literary translingualism, defined as the practice of writing literature in a second language, is by no means new, it is only in the past two decades that a specialized research field has emerged around the phenomenon. Synthesizing recent developments and drawing on several existing research strands, this study sets out to examine translingual writing in French in its contemporary expressions, with a particular focus on the novel. Do contemporary writers understand their translingualism differently from their predecessors? Can translingual studies be productively put into dialogue with developments in world literature studies? And how should we understand translingual writing in relation to the theoretical “translingual turn” affecting literary studies more broadly? This dissertation argues that contemporary translingual writing in French must be understood as part of a wider shift affecting both creative and critical practices, as the forces of globalization prompt us to reassess the relationship between literature and its language(s).Following a theoretical discussion, the analysis chapters aim to shed light on contemporary understandings of translingualism as articulated in the poetics of three major authors. The chapter focusing on Nancy Huston’s bilingual novel, Danse noire, investigates forms of novelistic self-reflexivity that demonstrate a renewed attentiveness to translation as it underpins literary mimesis. What is here called her translational storytelling not only foregrounds the representation of diegetic languages, but also draws our attention to the hermeneutic processes and ethical implications of writing and reading stories which potentially reach beyond our own linguistic, geographic and social realms. The following chapter turns to the linguistic autofiction of Vassilis Alexakis. After establishing how Alexakis’ ambilingual practice – his alternation between writing in French and Greek – leads him to interrogate his own position within world literary exchanges, it analyses both his novel, Les Mots étrangers, and his collaboration on the bilingual anthology, Âtënë tî Bêafrîka. Paroles du cœur de l’Afrique, within the framework of an “uneven translingual event” (Helgesson & Kullberg). The final chapter considers the fact that Andreï Makine’s Le Testament français has come to be viewed as the archetypal French translingual novel. A reading of this novel alongside Makine’s pseudotranslations and pseudonymic works prompts an examination of the notion of translingualism as exophony, a voyage outside of the mother tongue, and of how such writing positions itself in relation to national, monolingual literary space.Previous studies of translingualism in a French context have tended to view translingual authors as language migrants, who abandon their mother tongue in favour of a monolingual literary production in French. Recent work has brought the focus back to the multilingual processes informing translingual creativity, but may have overestimated the capacity of such writing to transgress the monolingual paradigm. Drawing on work by critics such as Apter, Beecroft, Gramling and Yildiz, this dissertation shows how contemporary translingual poetics can be understood as at once the result of homogenizing forces which favour monolingual and “translatable” writing in major world languages, and as partaking in the emergence of new aesthetic practices seeking to register and respond to linguistic diversity in literature.
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| 28. |
- Edoff, Petra, 1984-
(författare)
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Managing offshoring of complex products : Strategy and capabilities
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Offshoring is a hot topic in the industrial and academic community over the last few years, evolving from a focus on manufacturing to product development and R&D. Offshoring refers to the process of sourcing and coordinating tasks across national borders and can include both in-house and outsourced activities performed by a supplier. There is a lot of research guiding the decision of what, where and how to offshore, but research on how to implement offshoring strategies is rare. The purpose of this dissertation is to contribute to the knowledge on how companies deal with offshoring in practice, relating to strategy, planning and routines. It discusses what type of capabilities that is needed to gain the benefits of offshoring implementations.The research builds on case studies from two multinational companies offshoring product development from Sweden to captive and offshore development centres in India and China through a series of interviews, review of business documentation and other types of active engagements over time.This research highlights how the development and implementation of offshoring can be better understood by focusing on the middle management in the organization and how they relate to the top management directives when implementing an offshoring strategy. The thesis contributes to existing theory by explaining offshoring as a process, situated in a certain context and time. It defines key routines and capabilities needed to facilitate offshoring of complex product systems. Including context, timing and sequence when analysing offshoring help explain why some organizations fail to implement offshoring initiatives.The companies had an iterative learning process to deal with offshoring, and inclusion of all levels in an organization was highlighted as a key success factor for the implementation of offshoring. The results extend current understanding of offshoring of complex products to Asia and provide useful guidelines for managers on the key issues they need to consider.
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| 29. |
- Edoff, Petra
(författare)
-
Organizational capabilities for managing the offshoring of product development
- 2011
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Large multinationals must continually innovate to produce products and services that meet the needs of a global market. In order to distribute work across multiple sites, they use techniques such as offshoring and outsourcing. This requires them to address organizational and cultural aspects to coordinate distributed product development activities. While these techniques have received great interest in business as well as research in recent years, as the latest trend is to send increasingly complex functions such as research, development and engineering (RD&E) overseas. When offshoring involves high value functions, the transitions occur rapidly, and the associated risks and costs of failing increase. In addition to the hidden costs of offshoring and outsourcing, there is a risk of losing core competences over time or spillovers of critical knowledge to competitors in the new market. Despite the criticality of succeeding with their offshoring efforts, little is known considering of how companies handle the process of distributing work globally, and the capabilities they develop to manage offshoring efficiently. The objective of this thesis is to explore the routines and capabilities that organizations´ need to develop to make offshoring an integral part of the management global RD&E. Two in-depth case studies are used to develop firm specific theories which can inform both the theory and practice of managing offshoring. Case A provides insight into a client-supplier relationship between the Swedish site of a multinational and its Indian service provider. The current challenges identified through the case study are paired with a retrospective analysis of the evolution of the decade-long relationship, to show how the cross-cultural interface has influenced the evolution of the relationship. With the assistance of a literature review, the findings are explained through the theoretical lenses of national culture, organizational culture and contextual factors. Case B provides insight into offshoring management in terms of a product management transfer from a Swedish site to a research center in China of the same multinational. Besides the insights into the transfer of responsibility for a complex product overseas, the case provides the base of an organizational capabilities framework for managing all stages in the offshoring process (decision, transfer, operations and governance stage). Four key capabilities were found to support the management of offshoring, namely; technological skills, process & tools, relationship management and knowledge management.
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| 30. |
- Eynian, Mahdi, 1980-, et al.
(författare)
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New methods for in-process identification of modal parameters in milling
- 2018
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Ingår i: Procedia CIRP. - : Elsevier. - 2212-8271 .- 2212-8271. ; 77, s. 469-472
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Tidskriftsartikel (refereegranskat)abstract
- Chatter vibrations encountered in machining can degrade surface finish and damage the machining hardware. Since chatter originates from unstable interaction of the machining process and the machining structure, information about vibration parameters of the machining structure should be used to predict combinations of cutting parameters that allow stable machining. While modal test methods, for example those with impact hammers, are widely used to identify structural parameters; the need for sophisticated test equipment is prohibitive in their use. Furthermore, dynamic properties of critical components of a machine tool may change as they get affected by cutting loads, material removal and spindle rotation. Recently few algorithms have been proposed that identify the in-process dynamic parameters by frequency measurements, thus avoiding these problems. In this paper, some of these algorithms are reviewed and their capabilities and limitations in processing am experimental data set are compared and discussed. © 2018 The Authors. Published by Elsevier Ltd.
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| 31. |
- Fotedar, Sunney, 1989, et al.
(författare)
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A criterion space decomposition approach to generalized tri-objective tactical resource allocation
- 2023
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Ingår i: Computational Management Science. - : Springer Science and Business Media LLC. - 1619-697X .- 1619-6988. ; 20:1
-
Tidskriftsartikel (refereegranskat)abstract
- We present a tri-objective mixed-integer linear programming model of the tactical resource allocation problem with inventories, called the generalized tactical resource allocation problem (GTRAP). We propose a specialized criterion space decomposition strategy, in which the projected two-dimensional criterion space is partitioned and the corresponding sub-problems are solved in parallel by application of the quadrant shrinking method (QSM) (Boland in Eur J Oper Res 260(3):873–885, 2017) for identifying non-dominated points. To obtain an efficient implementation of the parallel variant of the QSM we suggest some modifications to reduce redundancies. Our approach is tailored for the GTRAP and is shown to have superior computational performance as compared to using the QSM without parallelization when applied to industrial instances.
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| 32. |
- Fotedar, Sunney, 1989, et al.
(författare)
-
A decision-making tool to identify routings for an efficient utilization of machining resources: the decision makers’ perspective
- 2020
-
Ingår i: PLANs forsknings-och tillämpningskonferens.
-
Konferensbidrag (refereegranskat)abstract
- In the aerospace industry, efficient management of machining capacity is crucial to meet the required service levels to customers (which includes, measures of quality and lead-times ) and keeps the tied-up working capital in check. The proposed decision-making tool, described in this paper, aims to combine information and knowledge of manufacturing and logistics experts in a company to improve flow of materials through the factory. The material flow situation is different for a large aerospace tier-1 supplier as opposed to flow-based manufacturing company; when there is no pandemic or natural calamity, having relatively stable demand due to long-term contract is common, but there exists short-term demand variability. There is a complex flow of products at GKN Aerospace, as the products share machining resources, thus, resulting in uneven loads at machines and sometimes excess loading at certain machines. This along with short-term demand variability results in long queues in-front of machines which contributes with the biggest share of the total lead-time. Thus, long waiting times at one/many machine/s is common and may lead to bottlenecks in many places in the production pipeline. So, there is potential benefit in having rerouting-flexibility for products which can help in reducing queuing. However, qualifying a product for a new machine is time-consuming activity, and thus, should be done few years in advance. We propose a mathematical model aimed at improving some of these deficiencies of commonly used methods by facilitating balanced resource loading levels, i.e. to provide more degrees of freedom to the planner to absorb demand variations. The output provided by the model includes production routings in each time period (quarter) for the next 4–5 years; new qualifications to be done by technical staff for allocation of part types/products to machines which are not yet qualified/used for a given product. We keep the resource loading levels that are above a given threshold as low as possible and reduce the time/money spent for qualifying new allocations.
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| 33. |
- Fotedar, Sunney, 1989, et al.
(författare)
-
Mathematical optimization of the tactical allocation of machining resources for an efficient capacity utilization in aerospace component manufacturing
- 2019
-
Ingår i: Proceedings of the 10th Aerospace Technology Congress. - : Linköping University Electronic Press. - 1650-3686 .- 1650-3740. - 9789175190068 ; , s. 183-188
-
Konferensbidrag (refereegranskat)abstract
- In the aerospace industry, with low volumes and many products, there is a critical need to efficiently use available manufacturing resources. Currently, at GKN Aerospace, resource allocation decisions that in many cases will last for several years are to some extent made with a short-term focus so as to minimize machining time, which results in a too high load on the most capable machines, and too low load on the less capable ones. This creates an imbalance in capacity utilization that leads to unnecessary queuing at some machines, resulting in long lead times and in an increase in tied-up capital. Tactical resource allocation on the medium to long-range planning horizon (six months to several years) aims to address this issue by allocating resources to meet the predicted future demand as effectively as possible, in order to ensure long range profitability. Our intent is to use mathematical optimization to find the best possible allocations.
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| 34. |
- Fröberg, Joakim, et al.
(författare)
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Eliciting Critical Information in a Pre-Study Phase of Developing a Drive System Platform for Automotive Applications
- 2011
-
Ingår i: Proceedings of the International Conference on Industrial Engineering, Systems Engineering and Engineering Management for Sustainable Global Development.
-
Konferensbidrag (refereegranskat)abstract
- It is not straightforward to execute a pre-study and elicit all relevant requirements when faced with developing a mechatronic platform, such as a hybrid electric drive system, aimed for reuse in many advanced vehicles. We present analysis of probing critical information areas and how to identify shortcomings by studying an industrial case and compiling textbook recommendations. We present a method, synthesized from literature, for probing critical subjects for a mechatronic platform development initiative and outline related methods to address shortcomings. Recognizing the critical information in an early phase is one key to leverage complexity in an advanced product line effort.
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| 35. |
- Fröberg, Joakim, et al.
(författare)
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What Information on Business Parameters is Required by Embedded Software Developers to do an Effective Job?
- 2012
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Ingår i: Lecture Notes in Business Information Processing, vol. 114. - Berlin, Heidelberg : Springer. - 9783642307454 ; , s. 273-278, s. 273-278
-
Bokkapitel (refereegranskat)abstract
- Embedded software design is tightly connected to the functionality and goals of the system it is used to control. For mechatronic systems such as an in-vehicle automotive system, software developers require information on the system goals including business parameters to effectively decide on architecture and functionality. This paper presents results from an case of developing a hybrid electric drive system platform, and presents the information areas that software and system engineers do perceive as important to effectively perform design. We note that business parameters are sought for and elaborate on what information is required. We analyze what these needs are and elaborate on how to address them by using methods from the literature. We conclude that the effort of developing embedded software cannot rely on statically specified business parameters; rather these would be estimated and refined by interaction throughout the development cycle.
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| 36. |
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| 37. |
- Hoier, Philipp, 1988, et al.
(författare)
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Microstructural characteristics of Alloy 718 and Waspaloy and their influence on flank wear during turning
- 2018
-
Ingår i: Wear. - : Elsevier BV. - 0043-1648. ; 400-401, s. 184-193
-
Tidskriftsartikel (refereegranskat)abstract
- The present study deals with the influence of the microstructures of two wrought superalloys on the flank wear of uncoated cemented tungsten carbide tools in turning. Tool life tests have been performed in order to compare the flank wear development during machining of Alloy 718 and Waspaloy. Additionally, microstructural aspects, such as hardness, grain size as well as types and quantities of hard, abrasive phases have been determined and compared for both machined superalloy workpieces. The results show that Alloy 718 is associated with faster flank wear progression as compared with Waspaloy. The difference in wear is not likely to be the result of higher thermal and mechanical loads on the tool during machining Alloy 718. Characterization of obtained flank wear topographies after removal of adhered workpiece material revealed that abrasive wear is the dominant wear mechanism during machining both superalloys with the investigated cutting parameters. Varying extents of abrasive tool wear during cutting of the two alloys are therefore the likely reason for the different wear rates. In connection to that, significantly larger quantities of hard phases, specifically primary MC-type carbides and TiN-inclusions were found in the Alloy 718 workpiece which can explain the faster flank wear progression during machining this alloy.
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| 38. |
- Hultman, Hugo, et al.
(författare)
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Identification of variation sources for high precision fabrication in a digital twin context
- 2020
-
Ingår i: ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE). ; 2B-2020
-
Konferensbidrag (refereegranskat)abstract
- The aerospace industry is increasing its focus on fabrication in manufacturing, foregoing large castings to instead assemble and join smaller parts into final products. This increases the total amount of geometrical variation introduced during the production process, since the unique variation from each individual part can add to a propagating effect putting the final assembled product outside of tolerance limits. Geometry assurance and variation simulation has traditionally been applied as a part of the design process to develop robust manufacturing concepts that are as insensitive as possible to variation. A concept for geometry assurance has been proposed where variation simulation is conducted for each individual assembly using real measurements from incoming parts, making it possible to make adaptive adjustments to production parameters to optimize results. It is however not feasible to measure and simulate every aspect of the process. This paper provides a summary of relevant sources of geometrical variation for a high precision fabrication process, based on input from a fabrication process in the aerospace industry. Variation sources are analyzed and discussed from an industrial perspective, putting them in the context of an actual fabrication process as well as in the context of digital twins for geometry assurance.
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| 39. |
- Hultman, Hugo, et al.
(författare)
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Predicting Geometrical Variation in Fabricated Assemblies Using a Digital Twin Approach Including a Novel Non-Nominal Welding Simulation
- 2022
-
Ingår i: Aerospace. - : MDPI AG. - 2226-4310. ; 9:9
-
Tidskriftsartikel (refereegranskat)abstract
- The aerospace industry faces constantly increasing demands on performance and reliability, especially within the vital area of engine development. New technologies are needed in order to push the limits of high precision manufacturing processes for the next generation of aircraft engines. An increased use of in-line data collection in manufacturing is creating an opportunity to individualize each assembly operation rather than treating them identically. Welding is common in this context, and the interaction between welding distortion and variation in part geometries is difficult to predict and manage in products with tight tolerances. This paper proposes an approach based on the Digital Twin paradigm, aiming to increase geometrical quality by combining the novel SCV (Steady-state Convex hull Volumetric shrinkage) method for non-nominal welding simulation with geometrical data collected from 3D scanning of parts. A case study is presented where two parts are scanned and then welded together into an assembly. The scan data is used as input for a non-nominal welding simulation, and the result of the simulation is compared directly to scan data from the real welded assembly. Three different welding simulation methods are used and assessed based on simulation speed and ability to predict the real welding result. The segmented SCV method for welding simulation shows promising potential for this implementation, delivering good prediction accuracy and high simulation speed.
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| 40. |
- Hultman, Hugo, et al.
(författare)
-
Towards a digital twin setup for individualized production of fabricated components
- 2021
-
Ingår i: ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE). ; 2B-2021
-
Konferensbidrag (refereegranskat)abstract
- As the aerospace industry continues its shift towards digital manufacturing, an increased use of inline sensors and data collection is creating an opportunity to further optimize the production process. Measurements from individual parts make it possible to adapt each process to current conditions rather than running all processes nominally. This is sometimes described as individualized production as opposed to traditional mass production. The concept of a digital twin for manufacturing has recently gained more attention as a promising method for individualized production. A digital twin collects data from a real environment to create a virtual copy of a physical phenomenon, which can be used to predict how its real counterpart is going to behave. The approach has been proposed for a manufacturing environment where it would be used to predict the outcome of a production process. This could prove particularly useful for fabrication processes, a method used for making aero engine parts by joining large assemblies of smaller parts through welding. This paper presents functionalities that can be used to implement a digital twin in a high precision fabrication process, outlining different approaches for data collection, data analysis, and adaptive process adjustments. An example is shown where physical measurements are used to improve the predictive capabilities of a welding simulation in order to enable more accurate process adjustments.
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| 41. |
- Johansson, Peter E., Associate professor, 1978-, et al.
(författare)
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Let us measure, then what? : Exploring purposeful use of innovation management self-assessments.
- 2019
-
Ingår i: International Journal of Quality & Reliability Management. - 0265-671X .- 1758-6682. ; 36:10, s. 1734-1749
-
Tidskriftsartikel (refereegranskat)abstract
- PurposeThe purpose of this paper is to increase the understanding regarding how managers attempt to make purposeful use of innovation management self-assessments (IMSA) and performance information (PI).Design/methodology/approachAn interpretative perspective on purposeful use is used as an analytical framework, and the paper is based on empirical material from two research projects exploring the use of IMSA and PI in three case companies. Based on the empirical data, consisting of interviews and observations of workshops and project meetings, qualitative content analysis has been conducted.FindingsThe findings of this paper indicate that how managers achieve a purposeful use of PI is related to their approach toward how to use the specific PI at hand, and two basic approaches are analytically separated: a rule-based approach and a reflective approach. Consequently, whether or not the right thing is being measured also becomes a question of how the PI is actually being interpreted and used. Thus, the extensive focus on what to measure and how to measure it becomes edgeless unless equal attention is given to how managers are able to use the PI to make knowledgeable decisions regarding what actions to take to achieve the desired changes.Practical implicationsGiven the results, it comes with a managerial responsibility to make sure that all managers who are supposed to be engaged in using the PI are given roles in the self-assessments that are aligned with the level of knowledge they possess, or can access.Originality/valueHow managers purposefully use PI is a key to understand the potential impact of self-assessments.
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| 42. |
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| 43. |
- Larsson, Örjan, et al.
(författare)
-
The Third Wave of Automation : Critical Factors for Industrial Digitization
- 2014
-
Ingår i: Swedish Production Symposium 2014 SPS 2014. - Göteborg, Sweden.
-
Konferensbidrag (refereegranskat)abstract
- The scope of industrial automation is shifting into a third wave of automation based on extreme information availability, cyber-physical systems and data analytics. This paper present critical factors and way forward for the development of the Swedish industrial automation sector, both users and suppliers. Based on literature and practice studies, and a survey including some 40 respondents, ten factors for realising the third wave of automation was identified with four key factors: Technology, Processes, Business models and Competence. Finally, initial steps on a way forward are proposed for the development of Swedish automation industry and research.
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| 44. |
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| 45. |
- Malakizadi, Amir, 1983, et al.
(författare)
-
Inverse identification of flow stress in metal cutting process using Response Surface Methodology
- 2016
-
Ingår i: Simulation Modelling Practice and Theory. - : Elsevier BV. - 1569-190X. ; 60, s. 40-53
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, a methodology was presented to determine the flow stress behaviour of the work material within the range of strain, strain rate and temperature encountered during chip formation process by means of inverse modelling of orthogonal cutting operations. This approach was based on the concept of Design of Experiments (DOEs) and Response Surface Methodology (RSM). Initially, an extension of Oxley's machining theory incorporating the Johnson-Cook material model was integrated with RSM to accomplish a fast assessment of the material parameters. Having provided the material parameters by Oxley's machining theory, the optimum set of friction coefficients were determined through evaluation of the Finite Element (FE) simulation results. The final step involved direct integration of 2D FE models incorporating the optimum frictional boundary conditions with RSM to reassess the optimum set of material parameters. This approach was implemented to determine the constitutive parameters for wide range of materials including Inconel 718 in aged condition, AISI 1080 plain carbon steel and AA6082-T6 aluminium alloy. The calibration of material models using the presented inverse methodology led to a significant improvement in simulation results. The reasons for the robustness of the proposed inverse methodology were discussed.
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| 46. |
- Malakizadi, Amir, 1983, et al.
(författare)
-
The role of microstructural characteristics of additively manufactured Alloy 718 on tool wear in machining
- 2021
-
Ingår i: International Journal of Machine Tools and Manufacture. - : Elsevier BV. - 0890-6955. ; 171
-
Tidskriftsartikel (refereegranskat)abstract
- This study aims to provide a fundamental understanding of the role of microstructural characteristics influencing tool wear when machining Alloy 718 fabricated using Powder Bed Fusion (PBF). The effects of preferred crystallographic orientation (texture), shape and distribution of grains, local misorientation, type and amount of precipitates as well as the type, size and amount of abrasive carbides, nitrides and oxides on tool wear are investigated in as-built condition and after the standard solutionising and double-aging treatment. The microstructures of workpiece materials and the surfaces of worn tools were examined using different material characterisation techniques, including Scanning Electron Microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD). A dislocation-based approach was used to reveal the cumulative effects of the microstructural characteristics on deformation behaviour and the thermo-mechanical loads on the tools during cutting. The analyses suggest that texture and the extent of material work-hardening prior to the onset of crack formation markedly influence the amount of plastic work and thus heat generation when machining Electron Beam Powder Bed Fusion (EB-PBF) material. The higher heat generation in the cutting zones provokes thermally-induced wear mechanisms like diffusion-dissolution and oxidation. In addition, the larger amount of hard oxide inclusions present in EB-PBF material leads to higher wear by abrasion. In contrast to the prevailing experimental approaches in this field, the present investigation is built on a physics-based framework to understand the fundamental aspects that govern material deformation and heat generation in cutting and, consequently, tool wear mechanisms. This framework can be used for machinability assessment of any alloy manufactured by different additive manufacturing (AM) technologies and for optimising the process-chain, including printing strategies and thermal post-treatments, to improve the machinability of AM alloys by tailoring their microstructure.
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| 47. |
- Moberg, Christina, et al.
(författare)
-
De unga gör helt rätt när de stämmer staten
- 2022
-
Ingår i: Aftonbladet. - 1103-9000.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 48. |
- Parida, Vinit, et al.
(författare)
-
A study of how ICT capabilities can influence dynamic capabilities
- 2016
-
Ingår i: Journal of Enterprise Information Management. - : Emerald Group Publishing Limited. - 1741-0398 .- 1758-7409. ; 29:2, s. 179-201
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose - Prior studies have argued that small firms with dynamic capabilities can revise and reconfigure their internal resources to meet the uncertainties of their business environment. However, there is a lack of understanding of how they can develop such critical capabilities. In this study, we propose that small firms can employ information and communication technology (ICT) capabilities as a facilitator for developing dynamic capabilities. Thus, the study builds on resource-based view (RBV) literature and and information systems (IS) literature by examining the influence of ICT capabilities on the dynamic capabilities of small firms.Design/methodology/approach - Several hypotheses were tested by analyzing the survey data from 291 small high-technology firms in Sweden.Findings - The results reveal that ICT capabilities influence dynamic capabilities of small firms. More specifically, the ICT use for internal efficiency positively influences adoptive capabilities, collaborative use of ICT positively influences networking capabilities, and ICT use for communications positively influences both adaptive and innovation capabilities. Consequently, the results suggest that the different components of ICT capabilities facilitate the development of the different organizational capabilities that together represent dynamic capabilities and thus, can contribute to a small firm’s competitive advantage.Practical implications - This study has few implications for the managers and CEO’s of small high-technology firms. Firstly, by prioritizing ICT capabilities, small firms can benefit from the development of dynamic capabilities that will support them to meet the challenges of turbulent business environment. Secondly, because small firms usually lack internal resources (i.e., financial resources and competence), the study provides more specific direction on how they can strategically invest and build different components of ICT that will positively influence their adaptive, absorptive, innovative and network capabilities.Originality/value – The study provides an alternative view of how ICT capabilities influence the performance of small firms, and outlines how such capabilities influence the development of dynamic capabilities. Therefore, the study in hand contributes to the RBV and IS literature by specifically linking the components of ICT capabilities to dynamic capabilities and its related sub-capabilities.
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| 49. |
- RAZANICA, SENAD, 1988, et al.
(författare)
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FE modeling and simulation of machining Alloy 718 based on ductile continuum damage
- 2020
-
Ingår i: International Journal of Mechanical Sciences. - : Elsevier BV. - 0020-7403. ; 171
-
Tidskriftsartikel (refereegranskat)abstract
- A novel model for rigid visco-plastic flow and continuous damage evolution is proposed for the modeling and simulation of chip formation of the alloy 718. The model draws from a recent thermodynamically consistent damage coupled to elasto-visco-plasticity framework for ductile failure, which is advanced to purely dissipative flow stress problems in the DEFORM 2D\texttrademark platform. As opposed to standard models with direct damage-plasticity coupling, the present model describes this coupling through a visco-plastic damage driving energy. The effective material response is described by the Johnson-Cook model where onset of damage evolution is controlled by a modified Cockcroft-Latham failure criterion, facilitating a flexible modeling of serrated chip formation. By comparing the proposed continuous damage degradation model to the damage drop method in DEFORM 2D\texttrademark, the role of ductile failure on the chip formation is investigated. The model is calibrated and validated against experimental machining tests, where both continuous and serrated chip formation is observed for the alloy 718 depending on the cutting speed. From the experiment, cutting forces, chip shapes and tool-chip contact lengths were analyzed and compared to the model response. A good agreement between model and experimental results is obtained.
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| 50. |
- Salloum, Mohammed, et al.
(författare)
-
Managing change in performance measures – An inter-company case study approach
- 2012
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Ingår i: International Journal of Business Science and Applied Management. - 1753-0296. ; 7:2, s. 53-66
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Tidskriftsartikel (refereegranskat)abstract
- The field of performance measurement and management (PMM) is well filled with frameworks, models and guidelines addressing what to measure and how to design a performance measurement system (PMS). However, what has been less examined so far is how to ensure that PM evolve in tandem with their environments. Further, the few approaches available today are prescriptive and outlines how or what practitioners should do in order to manage change in their PM. Thus, a gap exists in understanding how organisations manage change in their PM in practice. Thus, the purpose of this paper is to outline and compare the approaches of three case companies for managing PM change. In order to fulfil the purpose of the paper, the data presented has been collected through the deployment of case studies. The choice of case studies as means for data collection stems from the possibility of an in-depth and holistic examination of the formulated phenomenon. All three case companies belong to the same company-group that operates within the transportation industry. The industrial footprint of the company is global with operations and sales spread out over the world. The findings suggest that all three companies have processes in place for managing change in PM. However, the approaches differ in design and context. Even though the case companies had different approaches in place to manage change in PM, they shared several commonalities. Commonalities were shared in the way of execution, process input and challenges in IT and culture. Furthermore, employee involvement seemed to be the biggest challenge for all three companies. The findings put forward in this paper are limited as they are confined to three companies from the same company-group. More studies, both from within and outside the company-group, are needed in order to establish a solid base of empirical data for generalisation. However, this paper makes a contribution both through describing how three companies manage PM change and through elaborating on the underlying factors affecting functionality.
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