To prevent a development error by operating logical check in response to a demand for the registration of maintenance data, and registering the maintenance data in a registering means when any problem is not present.

When maintenance data are developed, and a distribution diagram is displayed, and a screen operation is executed, the update processing of the system diagram is operated in response to this. When an operator ends the maintenance processing, the recording of the screen operation is outputted as text data for each case, and registered in a distribution server as maintenance data. Also, at the time of developing the maintenance data, the maintenance data are converted into a program format, and a differential program is generated. When this differential program is executed, the processing operated by an operator is quickly reproduced, and the updated system diagram is displayed. The processing operated by the operator is recorded in those maintenance data, and link information to a new facility is generated at the time of executing the differential program. Therefore, even when the development order is exchanged, any development error due to the abnormality of the link can not be generated.