| 摘要 |
PROBLEM TO BE SOLVED: To manage a history about past drawing information even if drawing information is updated. SOLUTION: When the graphic of a facilities drawing shown on a display 18 is eliminated, only the graphic data of a drawing file 28 is eliminated and data showing the position and update time of the graphic among attribute data related to the graphic are stored in a graphic file 30. When time information about the update time of the graphic is inputted from a keyboard 20 when the past history of the graphic is examined, attribute information agreeing with the time information is extracted from an attribute file 30, and the extracted attribute data are displayed on the window 56 of a display 18.
|
