Patent ID: 7472024

Claim:
A data analysis apparatus for evaluating a maintenance strategy for a plurality of devices, comprising: a database configured to store first case examples of the devices, each including inspection time information which indicates an inspection for which of a plurality of periodic inspection times has been performed, a degradation level of the device, operation characteristics of the device, and replacement information indicating whether the device should be replaced or not; a maintenance strategy storage configured to store a evaluation maintenance strategy including an evaluative inspection time which indicates a time at which a periodic inspection should be conducted instead of the plurality of periodic inspection times, an evaluation time indicating a time at which degradation of the devices is to be evaluated and which is later than the evaluative inspection time, in a case that the periodic inspection is conducted at the evaluative inspection time instead of the plurality of periodic inspection times, and a replacement condition indicating a condition for replacing the device based on the degradation level of the device; a degradation prediction model storage configured to store a degradation prediction model for predicting the degradation level of the device from the operation characteristics of the device; a base case example selector configured to select base case examples which are first case examples whose periodic inspection time precedes the evaluation time and having the replacement information indicating that the replacement should be conducted; a case example generation and selection unit configured to estimate by using the database an estimated number of devices that have already been replaced before the evaluation time to not exist in the database, obtain the degradation level at the evaluative inspection time of each of as many devices as the estimated number by using at least the former of the base case examples and the degradation prediction model, and generate first virtual case examples including the degradation level at the evaluation time of devices whose obtained degradation level at the evaluative inspection time does not meet the replacement condition based on the base case examples and the degradation prediction model, calculate the degradation level at the evaluative inspection time of devices whose first case example have same periodic inspection time as the evaluation time from the first case examples of those devices and the degradation prediction model, and select first case examples of devices whose degradation level at the evaluative inspection time does not meet the replacement condition; and an evaluator configured to evaluate the evaluation maintenance strategy by using generated first virtual case examples and selected first case examples.