A machine shop bought an expensive CNC Lathe that came with built-in computer running CAD/CAM software. I watched a video of a man programming and running the lathe.
most commerical cnc come with 'conversational programming' built into the interface. Notable is Pathpilot built on top of LinuxCNC on the Tormach machines. conversational lets the operator make "more scrap parts" by programming at the machine (-: the interface has all the basic operations, face, pocket, drill, bore etc, and as the operator defines each operation it is added to the end of the Gcode program. This works great for job shopping where you are only doing 1 or a few parts but for real production you want real CAD/CAM and then some hand optimization for processing speed so the machine can make the maximum number of parts per shift. This kind of optimization usually involves removing the Z retracts (on a lathe) between tool changes, reducing tool changes, or even figuring out that moving tools around in the turret can save time between tool changes.
some do, some don't. Tormach is commercial, so it Millright and they both have conversational interfaces.