Assembley is the process by which parts become products that do useful things. Yet the design of assemblies and the process of assembling them are not taught in universities. This book is the first to develop a systematic approach to modeling and design of assemblies. It addresses assembley on two levels. Assembley in the Small deals with the fundamental processes of assembling two parts using engineering fundamentals. Assembley in the Large develops a systematic theory for designing of assemblies as carriers of function, starting from methods for representing assemblies in a computer and including the basic properties of mechanical constraint. Important assembley analysis techniques such as predicting variation, Design for Assembley and generating assembley sequences are also covered.