The goal of this research is to develop the tools by which the impact of part design on manufacturing assembly can be fundamentally understood and continually improved. To this end, three objectives will be investigated: (1) develop the physics of part mating, with application to part design for flexible manufacturing assembly; (2) develop a measurement tool (dexterity) which would be applied to models of the workholding and handling aspects of the manufacturing process, analyze handling devices and synthesize assembly systems; and (3) experimentally demonstrate the usefulness of dexterity as a common measure of part feature design and manufacturing assembly tasks.