PURPOSE: To output the result in a short time by efficiently processing the data of sorting required for a user by reducing necessity to retrieve all related partial data at the time of data extraction.

CONSTITUTION: When there is a data extracting request from the user, the conditions of that data extraction are interpreted by a first output data deciding means 3. Corresponding to that decision, the suitable destination of data extraction is reported to a related data retrieving means 6 and a data retrieving means 7. For example, when the user requests data in an 'installation group', the output data deciding means 3 instructs the data retrieving means 7 to retrieve only an installation group data base 9. Thus, the data extracting request of large sorting is speedily responded to without retrieving all the related partial data. Therefore, the collecting conditions of large facilities can be immediately recognized even in the case of a large scale plant.