Synthesis Thought Processes in Design

In this paper, we discuss what properties the synthesis process should have as a thought process and show a tentative synthesis theory. Instead of universality and minimality for knowledge for analysis, knowledge for synthesis in design needs physicality, unlikeness, and desirability. Physicality ensures possibility of existence, while unlikeness and desirability ensure newness, i.e., unlikeness is for ensuring that an artifact is different from other existing artifacts, and desirability for ensuring that it has reason to create newly. Then we show a formalization for synthesis theory that has the above characteristics. It is based on our design process theory in which a design process is an iterative logical process of abduction and deduction on design solution, its properties and behaviors, and knowledge on objects. Synthesis theory for design is defined as reconstruction process of design experiences, each of which contains the logical design process. It consists of three steps, i.e., (1) collecting design experiences; (2) building a model that includes the collected design experiences, and (3) minimizing an element that designers want to find newness.