A weighted rough set based fuzzy axiomatic design approach for the selection of AM processes

Additive manufacturing (AM) or 3D printing, as an enabling technology for mass customization or personalization, has been developed rapidly in recent years. Various design tools, materials, machines and service bureaus can be found in the market. Clearly, the choices are abundant, but users can be easily confused as to which AM process they should use. This paper first reviews the existing multi-attribute decision-making methods for AM process selection and assesses their suitability with regard to two aspects, preference rating flexibility and performance evaluation objectivity. We propose that an approach that is capable of handling incomplete attribute information and objective assessment within inherent data has advantages over other approaches. Based on this proposition, this paper proposes a weighted preference graph method for personalized preference evaluation and a rough set based fuzzy axiomatic design approach for performance evaluation and the selection of appropriate AM processes. An example based on the previous research work of AM machine selection is given to validate its robustness for the priori articulation of AM process selection decision support

Applying lean principles and set-based approaches in product development

The research described in this thesis addresses the problem of transformation to lean product development (LPD) and how to introduce and support the use of set-based design (SBD) in the concept development process. The original description of SBD does not define how to generate, evaluate and reduce a set of design solutions. Evaluation of solution candidates, which are too complex to be analytically verified, or are driven by qualitative criteria, has here been given special attention, particularly in cases when methods utilising human judgment may be needed. For some products, the solution space can consist of both principally different alternatives and parameterised variants of these. The question here is if established methods can be combined and introduced in an efficient way to support an SBD process for development of such products, when driven by both quantitative and qualitative criteria.The research approaches used are:-\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 a two-case study (Yin, 2009), -\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 the design research methodology (Blessing and Chakrabarti, 2009), and -\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 the scientific work paradigm (J\uf8rgensen, 1992), the last two combined with multiple case studies. Also, elements of action research (Oosthuizen, 2002) are used. The results show that the principles and introduction of LPD were experienced as positive by participating practitioners in the conducted case studies. It was furthermore shown that SBD can be introduced and applied in a workshop at team level within a time frame of one or two working days if the design problem at hand is not too complex. Another result is that SBD can be combined with and supported by established methods such as creative and systematic methods for synthesis, enhanced function-means modelling, axiomatic design, extended causal diagrammes, interactive evolutionary algorithms (IEA) and Pugh matrices for generation, analysis, evaluation and reduction of a solution space of design alternatives and variants of these. Both qualitative and quantitative requirements can be handled. The conclusions are that a transformation to LPD is facilitated by information about good examples and internal support by management. Also, the existence of a lean enthusiast in the organization and an appropriate implementation plan supports a transformation to LPD. A function to maintain the LPD system as well as influence of the lean principles are valuable guides on how to use LPD.\ua0 Also concluded is that a seamless, efficient process, applying set-based principles, for synthesis, evaluation, and reduction of a solution space of design alternatives can be created by combining enhanced function-means modelling, morphological matrices, axiomatic design, causal diagrammes and Pugh matrices. Such a compound of methods can be introduced and applied in a workshop at team level within a time frame of one to two days when solving well-known and not too complex design problems. The workshop should be facilitated by an expert on the methods used and initiated and surveyed by a team manager. Furthermore, a solution space of parameterised design variants, with criteria that are either qualitative or too complicated to be numerically defined, can be generated, evaluated and reduced in such a process. By using a defined set of functional and constraining criteria, and applying axiomatic design and IEA, a variant solution space can be generated and refined. A set-up of the IEA that does not overburden the user should be preferred

Applications of Axiomatic Design in academic publications 2013-2018 : A Systematic Literature Review

Aksiomaattinen suunnitteluteoria on ollut kasvavan kiinnostuksen kohteena tiedeyhteisössä siitä lähtien, kun Nam P. Suh esitteli teorian 1990-luvulla. Siitä huolimatta, että aiheesta on tehty runsaasti aktiivista tutkimusta (muun muassa vuotuinen aksiomaattiseen suunnitteluteoriaan keskittynyt konferenssi), kattavia kirjallisuuskatsauksia on kirjoitettu vähän. Tämä tutkimus pyrkii osaltaan täyttämään edelläkuvattua aukkoa aksiomaattisen suunnitteluteorian tutkimuskentällä, keskittyen julkaisuihin vuodesta 2013 vuoteen 2018. Tutkimus on kirjoitettu jatkumoksi vuonna 2010 tutkijoiden Kulak, Cebi & Kahmaran (2010) julkaisemalle kirjallisuuskatsakuselle. Tämän vuoksi samankaltainen kategorisointi on implementoitu tähän tutkimukseen. Kategorisoinnin perusteina ovat käytetty aksiooma, sovellutusalue, metodologia ja määrittelytyyppi. Sovellutusalueisiin on tässä tutkimuksessa lisätty ’palvelut’ omana, uutena kategorianaan. Työssä esitellään lyhyesti aksiomaattinen suunnitteluteoria ja sen keskeiset osa- alueet, tärkeimpinä sunnnittelualueet, suunnitteluprosessi ja suunnitteluaksioomat. Metodologia-osiossa taustoitetaan systemaattisen kirjallisuuskatsauksen soveltamista tähän tutkimukseen ja kuvataan prosessin toteutus PRISMA-mallia käyttäen. Tutkimustulokset käydään lyhyesti läpi esimerkein kustakin kategoriasta. Tutkimusaineisto esitetään sekä lukuina, liitteenä että graaffeina. Näitä kirjallisuuskatsauksen tutkimustuloksia verrataan varhemman tutkimuksen vastaaviin. Sovelletun aksiooman suhteen merkittäviä muutoksia ei ole havaittavissa tämän tutkimuksen perusteella aikaisempaan kirjallisuuskatsaukseen verrattuna. Sovellutusaluessa, sitä vastoin, systeemisuunnittelun osuus on kasvanut merkittävästi edelliseen tutkimukseen verrattuna, kun taas ohjelmistosuunnittelun osuus on vastaavasti pienentynyt. Palvelusuunnittelun osuus on verrattain vaatimaton, joskin suurempi kuin esimerkiksi ohjelmistosuunnittelun. Tämän tutkimuksen perusteella suositellaan jatkotutkimuksia erityisesti aksiomaattisen suunitteluteorian sovellutuksista ohjelmisto- ja palvelusuunnitteluihin sekä mahdollisista syistä, miksi mainittujen sovellutusaljen osuus tutkimuskentässä on pienehkö.Axiomatic Design theory has been gaining growing interest within a design community since introduced by Nam P. Suh in 1990s. Despite an active research within the field, including yearly international conferences of Axiomatic Design, there is not many literature reviews made of academic publications of Axiomatic Design. This research aims to fulfil previously described gap on secondary research of Axiomatic Design, focusing on papers published between 2013 and 2018. The study is a continuum to previous paper published by Kulak, Cebi & Kahmaran (2010). Therefore, similar categorization based on applied axiom, application area, methodology and evaluation type is applied in this research. In application area, ‘services’ have been added as a new category for this research. Results are compared with previous study. In findings, no siginificant change has happened in applied axiom, Independece axiom still being clearly more popular within academic publications. In application area, however, there are noticeable changes compared to the previous study. Share of system design has increased while softare design has significantly decreased. Future research is recommended to further explore specifically applications of Axiomatic Design in software and in services