Why Mechanical Design Cannot Be like Vlsi Design

It is widely agreed that the design methods and computer support of VLSI design are generally more mature than those of mechanical items. Why is this so, and is there any hope of the gap being significantly closed? This paper argues that there are fundamental reasons, that is, reasons based on natural phenomena, that keep mechanical design from approaching the ideal of VLSI design methods. The argument is accompanied by examples and brief histories of the evolution of VLSI design methods and attempts to systematize mechanical design. Brief attention is also given to the paradoxical fact that VLSI design itself is currently receding from the ideal and taking on the flavor and problems of mechanical design. This paper is based on several reports and working papers with limited circulation. The one relied on primarily is [Whitney, Nevins, De Fazio and Gustavson]. The author wishes to acknowledge the contributions of his coauthors of that report. He also acknowledges the many discussions he had with people mentioned in the footnotes who enriched his approach to this topic.