Abstract: For adaptive control of cutting machining operations, measured quantities characterizing optimized productivity are utilized. These quantities are connected with the wear of the tool and with the wearing rate. To measure the wear, the face wear (also called crater wear) of the tool, its flank wear and its minor-flank wear are used. Other parameters used are: the dimensions of the workpiece, its vibrations, its deflection, its surface roughness, cutting force, and cutting power. In a calculating unit, the shortest time is calculated until a given wearing criterium is reached. This time, and cost constants for the machining process, are fed into a control unit for calculating the optimized (maximum) productivity, and for performing the machining operation with cutting parameters kept within predetermined values. Machining is interrupted for tool changing when one of said wearing criteria is reached.