Fundamental Processes of Mechanical Designers Based on Empirical Data

SUMMARY The fundamental processes of problem solving during the mechanical design activity are presented based on a study of human designers. The designers in this study solve problems by applying 10 specialized actions, called operators, which are grouped into the categories of ‘generate’, ‘evaluate’ and ‘decide’. These operators are applied in unique sequences of which 95% constitute the following four local methods: ‘generate and test’ (23%), ‘generate and improve’ (8%), ‘deductive thinking’ (33%) and ‘means end analysis’ (36%). Furthermore, cognitive activity is reduced to a hierarchical architecture of tasks and episodes which reflect the goal structure of the designer. These descriptions demonstrate the abilities and limitations of the human designer's problem-solving performance, yielding an insight into how the man-machine interaction of design automation can be improved.