When a manager uses an input device to input the inspected states of the degrees of soundness of a plurality of objects, a data receiving unit receives them as inspection data. A deterioration characteristic calculating unit calculates the average value of the deterioration characteristics of the objects based on data related to the degrees of soundness of the plurality of objects that is received by the data receiving unit. A heterogeneous parameter calculating unit calculates a heterogeneous parameter for each heterogeneous factor that cannot be observed or is difficult to observe, and causes a variation in the deterioration characteristics. A benchmarking unit evaluates the influence of the heterogeneous factors on the deterioration characteristics based on the heterogeneous parameters, and an output unit outputs the evaluation result.