To create a performance required patch list showing a patch which should be performed for changing an equal file before changing a file which is not backed up though it is changed by the patch.

It is determined (B1) whether at least one file shown by access file information in patch performance is not included in a backup required part shown by backup object information (NO), or any file shown by the access file information in patch performance is included in the backup required part shown by the backup object information (YES), and in the case of NO, patch identification information in the access file information in patch performance is included in the performance required patch list (B2).