PURPOSE: To simply implement test/debug of a built-up system dispensing with an actual hardware by operating an entry means or the like while observing an instrument installed flow diagram displayed on a display means of a system generating means so as to build up the system.

CONSTITUTION: The system requested by the user is built up by using a system generating means 1 while the system is displayed on a display means as an instrument installed flow diagram. The system consists of, e.g. an internal instrument having a function as a feedback regulator implementing PID control arithmetic operation, an internal instrument as a sequence regulator and an internal instrument having a switch function or the like. A process model simulating a controlled system by a process simulating means 2 is constituted in system to build up while displaying it on the display means as the instrument flow diagram. A test means 3 is activated when the built-up system is tested to connect the built-up system with the process model for the test. Thus, test/debug is implemented without using an actual controller (actual machine).