Feature recognition has been an active topic of research for many years, and is rightly considered to be a critical issue for effective CAD/CAM integration. However, full integration of Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) systems in industry has t yet been matured. Computer Aided Process Planning (CAPP) is one of the important obstacles to be overcome to bridge the gap between Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM). This book is concerned with understanding the problem of how to manipulate and extract information from solid Computer Aided Design (CAD) models by using neutral files and its further use in downstream manufacturing operations. Emphasis is placed on recognizing and classifying manufacturing features from the Boundary Representation (BREP) of solid models of mechanical parts with the help of the data exchange standards such as Data Exchange File (DXF) and Standard for Exchange of Product data model (STEP).