A systematic approach of design theories using generativeness and robustness

In this paper we build a systematic comparison of several formal design theories: General Design Theory, Axiomatic Design, Coupled Design Process, Infused Design and C-K theory. Each theory offers principles as well as mathematical assumptions and establishes propositions that we analyze through two main criteria: i) their generativeness, i.e. their ability to produce design proposals that are different from existing solutions and design standards; ii) their robustness, i.e. their ability to produce designs that resist variations of context. Using such framework, and focusing on the evolution of the mathematical assumptions of each theory, it can be shown that the development of design theories does not reflect radically different point of views about design. Instead, there is an evolution towards more generality and less dependency on predefined objects. They form altogether a consistent body of knowledge that has aimed to increase the generativeness of design without losing its robustness. Thus, Design science can be seen as the science of "generativity". The evolution of design theories is illustrated by applying each of them to the same brief: the design of a new camping chair.