Downloaded from orbit.dtu.dk on: Sep 24, 2021 Defining Interactions and Interfaces in Engineering Design Parslov, Jakob Filippson Publication date: 2016 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Parslov, J. F. (2016). Defining Interactions and Interfaces in Engineering Design. Technical University of Denmark. DCAMM Special Report No. S200 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Defi ning Interactions and Interfaces in Engineering Design PhD Thesis Jakob Filippson Parslov DCAMM Special Report No. S200 March 2016 Thesis for the degree of Doctor of Philosophy Defining Interactions and Interfaces in Engineering Design by Jakob Filippson Parslov Department of Mechanical Engineering Technical University of Denmark March, 2016 Defining Interactions and Interfaces in Engineering Design Jakob Filippson Parslov Section of Engineering Design and Product Development Department of Mechanical Engineering Technical University of Denmark Produktionstorvet, Bld. 426 B DK-2800 Kgs. Lyngby Denmark PhD Thesis ISBN: 978-87-7475-447-3 DCAMM Special Report No.: S200 © Copyright by Jakob F. Parslov All rights reserved 2016 ii iii Supervisor Niels Henrik Mortensen, PhD Head of Section, Professor Section of Engineering Design and Product Development Department of Mechanical Engineering Technical University of Denmark Co-supervisor Lars Hvam, PhD Professor Operations Management Department of Management Engineering Technical University of Denmark Company supervisor Tommy Bysted, PhD R&D Director New Product Development Radiometer Medical ApS Opponents Johan Malmqvist, PhD Dean of education MATS, Chair Professor Product and Production Development Chalmers University of Technology Christian Weber, PhD Dean of Department of Mechanical Engineering Technical University of Ilmenau Michael Wörösch, PhD Director of Systems Engineering GN Resound This PhD thesis was publicly defended on June 3rd, 2016 iv Abstract This PhD thesis focuses on the understanding and definition of interactions and interfaces during the architectural decomposition of complex, multi-technological products. The Interaction and Interface Framework developed in this PhD project contribute to the field of engineering design research. Developing complex, multi-technological products involves the joint effort of multiple engineering disciplines in order to arrive at an end product, which satisfies its requirements. A major challenge is however the fact that bringing together engineers from different technical backgrounds means that they have different conceptual viewpoints on the product and use different ‘technical languages’ to communicate. Some terms like an interface, is used frequently in engineering however with no commonly declared meaning and is thus subject to much interpretation across engineering disciplines. It is well-known that most problems arise at the interfaces during product development, which is why there is a need for a rigorous and multi-disciplinary treatment of the concept of interfaces as well as interactions. On the basis of a two-year case study at a medical device manufacturer, the role of interactions and interfaces in product family development has been investigated. The case study showed that for this particular case, interaction and interface descriptions represents the rationales needed to reuse documentation across multiple product variants. The interaction and interface descriptions thus become documents of legal matter and must therefore be unambiguously and completely described. Following this observation, a comprehensive and systematic literature review has been performed in order to investigate the definition and perception of an interface. The review resulted in a classification revealing 13 dominant perceptions of what an interface is from an academic perspective including the observation of an apparent confusion between the terms interaction and interface. In addition, a case example of a solenoid valve was examined in order to reason out the likely causes of problems occurring at interfaces. The case example showed that interfaces that reside at the boundary between engineering disciplines are vulnerable to misinterpretation and rework. Based on this understanding, this thesis presents a first principles, physics-based Interaction and Interface Framework, which provides a ‘common language’ across any engineering discipline for describing and communicating about interactions and interfaces in engineering design. The framework contains classifications of three key terms; interaction, interaction mechanism, and interface. Due to the first principles, physics-based approach to deriving the framework, it has been possible to arrive at a classification of interaction mechanism, which is mutually exclusive (no overlap) and collectively exhaustive (no gaps). This contribution changes the existing paradigm of reasoning about interactions and allows for an unambiguous architectural decomposition of a product. The framework further proposes an 8-step architecting approach explicitly articulating how to systematically apply the framework top-down thus enabling complete and unambiguous descriptions of interactions and interfaces throughout the system. A tool called an Interaction Specification Wheel (ISW) is introduced to support consistency in writing requirements and specifications. All of the contributions have been evaluated in an initial test, which indicated a positive effect on their ability to capture interactions and unambiguously specify them. Further research is needed to obtain statistical significance. Future research may investigate how to incorporate the framework into practice and further evaluate the high level effects. This will most likely require two or more case studies in real-life projects. v vi Resume Denne PhD afhandling omhandler forståelsen og definitionen af interaktioner og interfaces ved arkitekturnedbrydning af komplekse og multi-teknologiske produkter. Interaktions- og Interface Frameworket, som er fremkommet af dette forskningsprojekt, bidrager således til Engineering Design forskningsfeltet For at kunne udvikle komplekse og multi-teknologiske produkter som opfylder dets krav om ønsket funktionalitet og performance, er det nødvendigt med et produktivt samarbejde mellem forskellige ingeniørdiscipliner. En hovedudfordring er dog, at der ikke findes et fælles sprog for visse begreber såsom et interface (dvs. en grænseflade), hvilket resulterer i at forskellige ingeniørdiscipliner anvender deres egen fortolkning af begrebet. Alvoren af dette forstærkes yderligere af, at interfaces er det sted i produktet, hvor flest problemer opstår under udviklingen, hvorfor der er et udtalt behov for en stringent og multidisciplinær behandling af begrebet interface såvel som det nært beslægtede begreb interaction. Den overordnede rolle af interaktions- og interfacebeskrivelser er blevet undersøgt i et toårigt casestudie hos en medikoudstyrsproducent. Casestudiet viste, at i dette specifikke tilfælde, bliver interaktions- og interfacebeskrivelserne brugt som rationaler for genbrug af dokumentation på tværs af produktvarianter. Interaktions- og interfacebeskrivelserne bliver således ophøjet til dokumenter af juridisk karakter, hvorfor de nødvendigvis bør fremstå helt entydige og komplette. Som følge af denne observation blev der foretaget et omfattende og systematisk litteraturstudie for at undersøge definitionen og opfattelsen af et interface. Reviewet resulterede i en klassifikation med 13 forskellige opfattelser af hvad et interface er fra et akademisk perspektiv, herunder en erkendelse af en sammenblanding mellem begreberne interaktion og interface. Derudover blev et case eksempel af en solenoid ventil brugt til at udlede de sandsynlige årsager til at problemer opstår ved interfaces. Case eksemplet viste, at interfaces, som er placeret i grænsefeltet mellem tekniske discipliner, er følsomme overfor fejlfortolkning og bør håndteres intensivt. For at adressere de identificerede fænomener introducerer denne PhD afhandling et first principles, fysikbaseret Interaktions- og Interface Framework som giver et fælles sprog på tværs af alle ingeniørdiscipliner til at beskrive og kommunikere omkring interaktioner og interfaces indenfor Engineering Design. Frameworket indeholder klassifikationer af tre nøglebegreber; interaktion, interaktionsmekanisme og interface. Som følge af en first principles, fysik-baseret tilgang til at udlede frameworket har det været muligt at komme frem til en klassifikation af interaktionsmekanismer som er gensidig uafhængig (ingen overlap) og helt komplet (ingen mangler). Dette framework ændrer det eksisterende paradigme omkring at ræsonnere om interaktioner og interfaces og tillader en entydig nedbrydning af arkitekturen af et produkt. Frameworket