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- Johansson, Roger, 1966-, et al.
(författare)
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Assessing Flexibility : The Frequency and Horizon Approach
- 2001
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper focuses on flexibility in the area of flexible automatic assembly systems. Far-reaching research has been done in effort to develop flexible automatic assembly systems. A dilemma that appears in understanding the focus for these research projects is the immense amounts of flexibility concepts used. This paper proposes a structure for the concepts based on frequency and horizon for different events in an assembly system. The results are presented in a proposed “flexibility map”. Based on the “frequency and horizon approach” and the definition of flexibility as “the penalty of change” [1], an argumentation concerning what kind of flexibility is most valuable in an assembly system can be discussed. The paper also points out the demands for a flexibility that allows for de-coupling of high and low frequency events in a system. A clear distinction is made between dynamic flexibility and static flexibility. It is a well-known fact that the increase of the dynamic flexibility in an assembly system will decrease the static flexibility [2]. The paper ends with a proposal for decreasing the negative correlation between dynamic- and static flexibility. An objective for further research concerning whether a certain process within an assembly system affects certain flexibility is also presented.
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- Johansson, Roger, 1966-
(författare)
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Implementation of Flexible Automatic Assembly in Small Companies : Flexibility and Process demands
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis has its focus within Flexible Automatic Assembly (FAA) systems and its implementation in small companies. The small companies are an important part of a country’s industry and economy. The need for the small company to increase the technology level, in order to be competitive in a global market as a supplier, is evident. The prevailing competence and economical resources of most small companies are often limited, a fact which underlines the need for economical, technological and application flexibility for their assembly system solutions. Therefore, these needs could be viewed as the main objectives posed on solutions which claim to be flexible, such as FAA systems.The objectives for this thesis are:- to investigate the state-of-the-art in FAA systems; the primary focus of the investigation residing upon flexibility issues. Theoretical study.- to investigate the implementation process in a small company that tries to apply FAA technology, and observe the problems that must be solved. Empirical study.- propose an approach as to how FAA systems should be structured.As a prerequisite for the proposed structure, the state of the art within FAA systems is discussed with focus on flexibility. The work in this thesis is based on the hypothesis that if systems are developed with properties satisfying the SME needs, the FAA-systems would be user-friendlier both in an economical- and a competence perspective. Hence the need to evaluate the status of current FAA systems.The work attempts to illustrate, through the theoretical and empirical studies, that there are three main factors that limit success when implementing FAA systems in small companies: Competence acquisition, Product design and Strategy for implementation. Learning, or competence acquisition, is most often carried out in parallel with the actual use of the system. This extensive learning phase most often leads to the system becoming obsolete during its expected run-time (period of use). The product design is another area of interest as it often seems hard to motivate product changes to facilitate automatic assembly, especially if no system is at hand as a driving force. The work also showed that there is a lack of strategy for implementation of FAA. The understanding of the FAA system impact on the product development and manufacturing is not understood, thus, the implementation is treated as a local phenomenon in the assembly shop. Furthermore, the ii uncertainty concerning future development of products is reflected in short payoff times, which makes the economical justification of systems difficult.All of these factors have been misrepresented to date due to a loose application of the term flexibility, and its implications. Therefore, the work attempts to clarify the flexibility issues, in terms of the assembly process demands, and also proposes a new flexibility map.To facilitate implementation of FAA into small companies, a modular assembly system approach is proposed. The modules should be task oriented. By using a modular approach, the possibility to have a system that is easy to keep up to date with product development, is greatly improved and the risk to invest in dead ends will decrease. Furthermore, it should become simpler to find an optimal level of automation or to prioritise the flexibility efforts, and thereby reduce the cost for maintaining flexibility over the system lifespan.A way to develop a decision.making tool for prioritising the flexibility efforts is proposed by using a Penalty-of-Change curve, which exploits the proposed flexibility map as a base. The modular approach is a way to decrease the negative correlation between dynamic flexibility (on-line) and static flexibility (off-line), since too much dynamic flexibility otherwise tends to limit the possibility to change the system to new situations. The modular approach isolates this negative correlation within modules. The technological adaptability will increase if a modular system is used since the standardised interfaces between modules define clear borders between functions or tasks within a system. Furthermore, a modular approach facilitates stepwise knowledge acquisition since it will be natural to focus on modules instead of entire systems.A leading idea in this thesis is, that small and large companies have the same system demands at module level, which makes it possible to increase the market for standardised modules and thereby decrease the cost for such modules. In other words, standardised modules, instead of systems. Modular systems are not optimised in terms of a low cost/capacity ratio for a certain product generation, instead, the system is optimised towards, reconfigurability to be able to follow product evolution, or totally rebuild for new products. Which, in the long run, may lead to a low cost/capacity ratio. Therefore, a prerequisite for the use of modular systems is that the systems will operate in a frequently changing market where fast ramp-up are more important (to maintain the market share) than an optimised system for each product generation.
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- Johansson, Roger, 1966-, et al.
(författare)
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Modular FAA-SYSTEMS : A way to facilitate justification and implementation of FAA into small and middle sized companies
- 2002
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Small companies are the backbone of any nations industry and they are often sub contractors to major corporations, which set higher and higher demands on them. In order to survive they will inevitably be obliged to comply with the requirements [Onori et al., 2000]. In order to do so, one step is to increase their technology level. Therefore, this paper focuses on modular FAA in order to facilitate the implementation of FAA-systems into small companies. How well companies succeed in the implementation of a new technology in manufacturing depends largely on how well they understand the dependency between products and processes. Is it the right technology for the companies manufacturing system? What has to be done to the products in order to use this technology? A paradox is that new technology in manufacturing can often be justified only when a new product launch is planned. This is probably true also in the case of Flexible Automatic Assembly Systems (FAA) where the possibilities to introduce a well functioning system to use with existing products are very limited.
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- Johansson, Roger, 1966-
(författare)
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Understanding the product : Backtracking the QFD connections via the product structure
- 2020
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Ingår i: DS 101: Proceedings of NordDesign 2020, Lyngby, Denmark, 12th - 14th August 2020. - : The Design Society. - 9781912254088
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Konferensbidrag (refereegranskat)abstract
- The subjectivity involved when creating a Quality Function Deployment (QFD) and the need for companies to understand how their product is fulfilling the customer needs are the focus of this paper. Literature is pointing out the subjectivity when using QFD. Therefore, a method was developed and explored with the aim to try to backtrack and verify the QFD connections via the product structure and thereby reduce the uncertainty. The method calculates a connection strength value for the QFD by summoning connection strength values for three matrices: customer requirements to functions, the functions to technical solutions and technical solutions to product properties. The model was implemented in a relation database and tested using a simple product. The test shows some promising results but also shows sources to uncertainty. Some identified reason for uncertainty were for instance unbalanced matrices, difficult estimates of ratios and redundancy in matrices. The test shows that by working with the model and try to understand why the model gives different results than the QFD gives a better understanding of the product.
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- Sandahl, Johan, 1974-, et al.
(författare)
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Överdrivna slutsatser om gymnasieelevers demokratikunskaper
- 2022
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Ingår i: Skola & Samhälle [S.O.S] Webbtidskrift. - : Föreningen Skola & Samhälle - webbtidskrift. - 2001-6727.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Rapporten från Stiftelsen Rättsfonden om gymnasieelevers kunskaper om demokrati har både metodologiska och teoretiska brister. Eftersom rapporten saknar stöd för flera av de rekommendationer som lämnas är risken att föreslagna förändringar inte gör någon skillnad eller i värsta fall leder i fel riktning, skriver Johan Sandahl med flera, alla forskare i samhällsvetenskapernas didaktik.
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