The Structure of Designs

The role of design descriptions is reviewed particularly in providing connections between product and process. The relations among the parts of descriptions represent the structure of designs. We consider the particular case when the parts form a closure structure and derive conclusions about the topology of descriptions. Following the scheme adopted for shapes and shape grammars we show that closure structures are a direct consequence of the primary role of relations in descriptions. Design processes use descriptions both individually and in combination. The different descriptions of a design display a partial order. It is shown how to combine descriptions into new descriptions. Further, multiple attribute descriptions including, for example, shape and associated properties, are constructed. Their structures are represented algebraically.