A control device determines, every control cycle, whether or not process values stored in a time-series manner satisfy a predetermined event condition. When the event condition is satisfied, the control device causes a chapter associated with the satisfied event condition to be stored in correspondence with time information that specifies the control cycle. The control device determines a target section with the time information in correspondence with a chapter that satisfies an extraction condition being defined as the reference, and extracts time-series data of the stored process values included in the determined target section.