Environment-Based formulation of Design Problem

This paper proposes a formal definition of design problem using the axiomatic theory of design modeling. Based on the concept of product system and an informal description of design problem, a design problem is formulated into three parts: environment, structural requirements, as well as performance requirements. On the basis of this formulation, both structural requirements and performance requirements are related to product environment, which is divided into natural, built, and human environments. As a result, product environment is identified as the source of product requirements. An environment-based formulation of design problem is thus developed. This formulation implies that both design problem and design solutions are included in a product system. The design governing equation is formulated to capture the interdependence relation between product problem and product descriptions along the design process. An example of rivet setting tool design is used to illustrate the mathematical formulations throughout the paper.