PURPOSE: To re-execute required input data as needed by reading data over a range instructed from the outside and controlling the data over this range so as to reproduce the operation of an operator within a range instructed from the outside.

CONSTITUTION: When a command corresponding to the system of the operator is received, an input part 1 outputs that command to an interactive control part 2. The interactive control part 2 analyzes the input data received from the input part 1 and controls the operation of the entire system according to the result. Namely, the interactive control part 2 controls a data generation update part 6 and updates a display indication part 7 and a CAD data base 8. A re-execution control part 3 controls the re-execution of the operation by writing input data through an operation history input/output part 5 to a history data base 4 or reading input data from the history data base 4. Thus, the required input data can be re-executed as needed.