Automation is the technology of using computerized or automatic equipment and devices, at different levels, to perform, execute, and control different functions of manufacturing. Fixed program automation, also called hard or fixed-position automation, performs a certain operation or series of operations on a particular part or family of similar parts. Classical manufacturing systems, such as job shops, employ general-purpose machines, adding some flexibility to the different jobs and operations that typically require different setups and process sequences. Unmanned cells can be viewed as a cooperating collection of machines, assisted by an automated measuring system and an automated loading/unloading device, such as a robot. These machines and devices are controlled by a computer or a cell controller. The advent of computers and computer technology and their emergence in manufacturing have resulted in the development of many technologies that have helped the manufacturing industry realize dramatic increases in productivity and profitability.