THE MEASUREMENT OF A DESIGN STRUCTURAL AND FUNCTIONAL COMPLEXITY

The complexity of a design process or a design artifact substantially influences their performance. When evaluation of terms such as ''desig n complexity'' and its ''quality'' is addressed in studies, it is ofte n performed in an ad hoc manner. This paper attempts to remedy this si tuation by articulating two definitions of design complexity (structur al complexity versus functional complexity), their associated value me asures, and the relationships between them. The structural definition states that a design complexity is a function of its representation. D efining design complexity in the structural way provides quantitative techniques for evaluating vague terms such as ''abstraction level,'' ' 'design form's size,'' and ''designing effort.'' The functional defini tion states that a design complexity is a function of its probability of successfully achieving the required specifications (functional requ irements and constraints). The proposed measurable metrics provide a p roper basis for evaluating each step of the design process, and accord ingly recommends the direction to follow for design modification and e nhancement. It also provides a framework for comparing competing artif acts (the output of a design process). The paper concludes by discussi ng the scope of the measures.