The revolutionary change in factory production techniques and management that is predicted to take place by the beginning of the 21st century will require unprecedented involvement of computer controlled system in the production process. Development of Computer Numerical Control (CNC) is an outstanding contribution to the manufacturing industries. With the help of CNC technology, it has been possible to integrate production equipment into a totally computer controlled environment. The present generation of CNC machine tools is designed to meet the requirements of high productivity, flexibility and reliability to produce components of consistently high quality and accuracy combined with reduction in manufacturing cost. So it becomes essential to update the knowledge of academicians & practicing engineers in the areas of CNC programming and maintenance.