Data processing apparatus and data processing method

A data processing device is provided with: a dividing unit that divides a target period into a plurality of operation periods in accordance with operation conditions; a determination unit that determines a standard condition, which is a standard operation condition, during each operation period; a calculation unit that divides each operation period into a plurality of performance-constant periods in which the performance of the target device is constant, screens the time-series data on the basis of a standard condition for each performance-constant period, and calculates a predetermined representative value on the basis of the time-series data extracted by the screens; and a correction unit that sets a repetition period including a boundary between two adjacent operation periods, screens the time-series data in the repetition period for each standard condition on the basis of each standard condition determined for the two operation periods, and corrects the repetition period based on the result of calculating