Machine-tool-state determination system and machine-tool-state determination method

A machine-tool-state determination method to be executed by a system that manages a machine tool having a rotation mechanism for processing a member, the system including a sensor configured to acquire a state value from the machine tool, and an analysis device including a processor and a memory connected to the processor, the machine-tool-state determination method comprising:

• performing spectral analysis with time series data of the state value, to extract a rotational frequency of the rotation mechanism and a harmonic wave to the rotational frequency, with the analysis device;
• calculating a ratio of an amplitude of the rotational frequency to an amplitude of the harmonic wave, with the analysis device;
• generating feature-amount data including the state value and the ratio as feature amounts, with the analysis device;
• performing clustering with the feature-amount data, with the analysis device;
• and
• determining a state associated with the machine tool, based on a result of the clustering, with the analysis device.