A screen layout corresponding to a transaction routine is input to a FORM, and an item and a code of design information corresponding to a screen input are generated as a table. A location of the screen input is associated with a record in a design information table, and the design information table is searched for based on the screen input to display a screen output, in a program design process prior to the program manufacturing process, so that pseudo operations of the transaction routine are performed on the screen. The present invention reduces an amount of feedback after a program is manufactured, by displaying a screen in a similar manner as in actual program execution, and verifying the program, in a program design process prior to a program manufacturing process of a transaction routine, and also makes program generation efficient, by inheriting data from the design process to the program manufacturing process.