Papers by Mikael Rosenqvist
Chalmers University of Technology, 2017
Geometrical variation affects all mass-produced products. This variation will lead to deviations ... more Geometrical variation affects all mass-produced products. This variation will lead to deviations from the nominal design of the product both in terms of aesthetical and functional properties. Geometrical variation originates either from the manufacturing of the parts or from the assembly process. In order to minimize the effect of variation robust design principles are often used. Finally, a number of existing research gaps are identified for further research.
Procedia CIRP, 2014
The manufacturing industry is focused on geometry assurance. Much of the virtual geometry assuran... more The manufacturing industry is focused on geometry assurance. Much of the virtual geometry assurance is done in Computer Aided Tolerancing (CAT) tools. Earlier research shows that assembly complexity influences the product quality but is not considered when geometry systems (locators and tolerances) are defined. Further previous research shows CAT simulations do not predict all the variation and therefore additional factors need to be included to improve accuracy. In this study, a robustness value for a geometry system solution based both on geometrical sensitivity and manual assembly complexity has been introduced. Calculation methods have been tested and implemented in a CAT tool using a real industrial case.
Experience has shown that new research does not reach out to companies and organizations in Swede... more Experience has shown that new research does not reach out to companies and organizations in Sweden as desired. The spread and application of useful research results was found to be limited to relatively few companies. The situation is similar across the EU according to investigations. This means that many improvement possibilities are missed and probably also increased profitability and competitiveness. In order to explore the underlying reasons for this nineteen Swedish companies were asked about participation in an interview study. Nine agreed to participate and interviews among upper level management were accomplished in order to investigate how new knowledge was acquired and implemented. The interview study included 18 semi-open questions about: organizational relationships; decision levels; distribution of responsibility; cooperation between different departments; successful implementation factors; responsibility for ergonomics issues; management of assembly-related errors and ...
The purpose of this paper is to explore how a recently developed method for evaluation of the imp... more The purpose of this paper is to explore how a recently developed method for evaluation of the impact of assembly complexity on manual assembly concepts should be used, by whom and how this would fit into an industrial product development process. The explored method incorporates both sensitivity to geometrical variation and assessment of assembly complexity and is integrated into the CAT (Computer Aided Tolerancing) tool RD&T. A baseline of a generic six phase product development procedure is summarized with focus on the part of the process that handles geometry assurance; the geometry assurance process. The result is a proposed working procedure for proactive geometry assurance considering manual assembly complexity as a part of a geometry assurance process. The proposed working procedure supports the development of products that have a high level of geometrical robustness and a low level of manual assembly complexity resulting in higher quality, less costs related to poor quality ...
Earlier studies have demonstrated strong relationships between manual assembly at high physical l... more Earlier studies have demonstrated strong relationships between manual assembly at high physical load levels and increased amounts of quality errors compared to assembly at low physical load levels. A recent Swedish interview study indicated that assembly complexity is also of importance for the assembly quality. The objective of this study was to examine the significance of complexity and the relationships between ergonomics, assembly complexity and quality by analyzing manual assembly tasks in car manufacturing. The results showed several significant correlations between ergonomics and assembly complexity, assembly time, failures and costs.
This study aimed at comparing two methods for assessing manual assembly complexity, the CXB consi... more This study aimed at comparing two methods for assessing manual assembly complexity, the CXB considering basic assembly complexity from product design perspective and the CXI, which assesses complexity as perceived by operators in production. The objective was to see if and how the two methods overlap. The results showed that they had some assessment criteria in common but that other criteria differed and covered different areas of interest. Both method approaches are important for a manufacturer to manage in order to create sustainable assembly conditions, good working conditions and reduce errors in manual assembly.
Geometrical variation affects all mass-produced products. This variation will lead to deviations ... more Geometrical variation affects all mass-produced products. This variation will lead to deviations from the nominal design of the product both in terms of aesthetical and functional properties. Geometrical variation originates either from the manufacturing of the parts or from the assembly process. In order to minimize the effect of variation robust design principles are often used. In early product development the majority of the properties in the system solutions are fixed and to change these later in the product development will be costly. In order to verify the system solution (locating scheme and tolerances), different simulation techniques are used to predict the behavior of the product. This is done using virtual tools, for example Computer Aided Tolerancing (CAT). In order to gain confidence for such tools it is very important that the simulation results are accurate and that they capture all factors that influence the product. In this thesis the focus has been on geometry as...
The objective in this study was to explore how assembly ergonomics and geometry assurance issues ... more The objective in this study was to explore how assembly ergonomics and geometry assurance issues were regarded by manufacturing companies. Therefore, 85 persons in total of which 21 was geometry engineers in five manufacturing companies were interviewed. Their answers show good awareness of the implications of poor assembly ergonomics but this does not always reflect the system solutions created. Further ergonomic requirements cannot contend with geometrical requirements, geometry has priority over ergonomics when they are in conflict. The improvement focus should be in the early development phases, mainly through the use of better virtual tools including calculation of quality costs, by training, new cross functional working procedures and through lessons learned.
Experience has shown that new research does not reach out to companies and organizations as desir... more Experience has shown that new research does not reach out to companies and organizations as desired. Thereby many improvement opportunities, increased profitability and competitiveness are probably missed. In order to investigate the underlying causes an interview study in Swedish companies was made. The results showed different reasons in large and smaller companies. The overall conclusion was that dissemination of academic knowledge and associated need of (external) implementation support must be better adapted to varying conditions in companies.
International Journal of Production Research
International Journal of Industrial Ergonomics
Volume 2B: Advanced Manufacturing, 2015
International Journal of Production Research, 2016
Increasing international competition between companies has put high focus on cost-cutting actions... more Increasing international competition between companies has put high focus on cost-cutting actions at all levels in companies and organizations. In product development there are many design requirements to meet and often tough project budgets to keep. Requirements that are considered not profitable will often be neglected, which often affects assembly ergonomics. The objective of this study is to demonstrate the relationship between ergonomics, assembly related quality errors and associated costs and develop a cost-beneficial assessment model. The results showed that ergonomics high risk issues had 5-8 times as many quality errors as low risk issues and the earlier risk issues were found the less were the action costs. A model for cost-benefit analyses was developed based on the obtained quality data.
Earlier studies have demonstrated strong relationships between manual assembly at high physical l... more Earlier studies have demonstrated strong relationships between manual assembly at high physical load levels and increased amounts of quality errors compared to assembly at low physical load levels. A recent Swedish interview study indicated that assembly complexity is also of importance for the assembly quality. The objective of this study was to examine the significance of complexity and the relationships between ergonomics, assembly complexity and quality by analyzing manual assembly tasks in car manufacturing. The results showed several significant correlations between ergonomics and assembly complexity, assembly time, failures and costs.
Volume 12: Systems and Design, 2013
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Papers by Mikael Rosenqvist