Models of designing

Many authors have proposed theories, models and methods in their search to explain or improve upon aspects of design practice.This field of literature, commonly known as design methodology, is primarily concerned with: ...the study of how designers work and think; the establishment of appropriate structures for the design process; the development and application of new design methods, techniques and procedures; and reflection on the nature and extent of design knowledge and its application to design problems. (Cross, 1984) Despite the extensive research undertaken since the 1950s, there is no single model which is agreed to provide a satisfactory description of the design process (Bahrami and Dagli, 1993). Likewise, there is no 'silver bullet' method which can be universally applied to achieve process improvement. Instead, most methods have a well-defined and often relatively narrow focus, ranging from the generation of mechanism concepts (e.g. Pahl and Beitz, 1996) through to the management of project risk (e.g. Baxter, 1995). Even so, implementation and use of such methods is often problematic, as experienced by Bucciarelli (1996). In this chapter, some popular approaches to the design process are presented and their practical relevance is discussed.Throughout the chapter, a classification framework is developed to support the discussion and to relate the diverse range of forms exhibited by these models.