External procedures in design problem solving by experienced engineering designers – methods and purposes

摘要

In the creative early phases of design problem solving, several kinds of external –nespecially manual – procedures of thinking (‘externalizations’) are applied. Thisnwas mainly shown in experimental settings for tasks of architects. We analysednthe kinds and the reported purposes of externalising in the everyday work ofnexperienced engineering designers. Three field studies with different samples ofnengineers (n紏55) show: the majority of experienced designers reported thenapplication of simple low-cost externalising (especially manual sketching andnimpromptu-prototyping) in their everyday work mainly for memory relief,ncommunication and generation of ideas. Different mental processes in the earlynphases of engineering design require different kinds of externalising to supportnthem. Simple low-cost externalisations offer most perceived support for communicationnand sophisticated ones (e.g. manufactured prototypes) for the evaluationnof solutions. The results based on retrospective memory reports of engineers arenconfirmed by self-records of an ongoing conceptual design process and thendocumented frequencies of different kinds of externalising.