At Aeromet, operators run the machine tools but don’t program them. There is a good reason for this, as Mr. Wahlberg explains. When the shop first started integrating CNC machines many years ago, operators were trained to perform shopfloor programming at the machine. Now, a CAM program is created for every job that runs through the shop. The CAM programmers also create instruction packets that clearly explain how each job should be set up and run. Tools are preset, tagged and placed on a cart for the operator, too. This enables operators with modest experience to run most jobs in the shop. Plus, if a problem arises, the process is deemed to be at fault, not the operator. Knowing this, operators don’t need to stand and watch the machine mill or turn parts, freeing them to tend multiple machines. In addition, this strategy prevents “experienced” operators from tweaking the program on the fly, because the time needed to make the change is oftentimes greater than the potential time savings after implementing the change. That said, operators are encouraged to write suggested process changes directly on the job’s instruction packet for consideration later by the programmer who will review the packet if that particular job happens to repeat.

http://www.mmsonline.com/articles/operators-operate-programmers-program