Relearning necessity determination method and relearning necessity determination device of diagnostic model in machine tool, and computer readable medium

A relearning necessity determination device that determines a necessity of relearning of a learned diagnostic model in a machine tool, the device comprising:

• a machining abnormality diagnosing unit configured to determine normality or abnormality of machining using the diagnostic model generated through machine learning;
• a tool usage storing unit configured to store a cumulative cutting time or a cumulative cutting distance of a tool mounted to the machine tool as a tool usage;
• a tool-usage-at-abnormality-diagnosis storing unit configured to store the tool usage when the machining abnormality diagnosing unit diagnoses the machining as machining abnormality;
• and
• a relearning necessity determining unit configured to determine the necessity of the relearning of the diagnostic model based on a frequency distribution of the tool usage stored in the tool-usage-at-abnormality-diagnosis storing unit.