PURPOSE: To eliminate trouble of data re-input and to efficiently perform the input operation by introducing the processing which changes an initial value information file, and arbitrarily initializing data to be reused or be always fixed by a user.

CONSTITUTION: Program information consists of program data 2 constituting programs and program management information 1 which manages and explains programs. A program generating system 10 segments pertinent program management information 1 into a file as initial value information and reads in initial information 3 at the time of program generation and changes only required parts to generate management information. Initial information 3 of program management information can be arbitrarily changed on the execution of operator's work. Thus, the time of input operation of definition essential information is shortened to improve the efficiency.