An operational control method is provided for a machine tool that includes a plurality of tool holders with a cutting-tool. The machine tool relatively moves the tool holders with respect to a workpiece to process the workpiece. The operational control method includes determining whether an abnormality has occurred in the cutting-tool during a processing or not, determining whether a simultaneous processing in which at least two or more of the tool holders perform the processings to an identical workpiece is being performed or not and whether the cutting-tool having the detected abnormality is the cutting-tool that is performing the simultaneous processing or not when the abnormality is detected, and causing the tool holder with the cutting-tool having the detected abnormality to take an abnormality avoidance operation and another of the tool holders to take a response operation based on a determination result at the determining of the simultaneous processing.