In this post I give an overview how to organize your CNC programs structure and what is the difference (in Total Engineer) between a CNC program and an operation.
A CNC Operation lets you define the type of the machining process like: milling, turning, drilling etc. and the corresponding parameters while a CNC program allows the user to specify some general characteristics (process parameters) of the process like: feed values, security distances etc. A CNC program also defines the tool and the machine which will be used. In this context the user can create sub-programs and decide whether they should inherit the parent process parameters, the tool and the machine.
For example, if you need a 10 mm milling cutter for 80% of the roughing process you would select the 10-mm-cutter in your parent CNC program (Roughing in the picture above) and then choose the child program (CNC Program) not to inherit the tool but to use the 5-mm-cutter.