Abstract: An ordinary person in charge is enabled to easily construct or modify a business processing system only by making a business flow diagram indicating the flow of the business to be adaptable to the contents of the business of the department to which the person in charge belongs if the person in charge understands the business system and slips and vouchers which are daily used without a necessity of requesting a system engineer having exclusive knowledge about programming to design the business processing system. Thus, a required business process can be performed. When the business flow diagram indicating the flow of each business in the own department has been made, a business constructing system analyzes the business flow diagram to make a slip registration card, an original register registration card and a voucher registration card.