PURPOSE: To mitigate the operator's burden and enhance the reliability and maintainability of the system.

CONSTITUTION: The control assisting apparatus has a data-base automatically building-up means 5 for automatically preparing mode information and line information on the basis of image screen description information 3, and path- information display means (15, 16, 17, 22, 24, 26) for displaying the contents of path information prepared on the basis of line information on the display device as a graphic image screen. The computer takes up necessary information from the picture image and automatically builds up a data base.