In the fall of 2008 we introduced Machining Navi, a group of operator support features that focused on suppressing chatter. This new “chatter stop” function was sensational, but in actual machine shops chatter does not occur that often. Machine shops with superior know-how were already taking solid measures to counter chatter, but stopping chatter and raising productivity were not directly linked. It then struck us that having the machine not just control chatter but also quickly identify the optimum cutting conditions (cutting speed [sfm]) would lead directly to improved productivity.