Abstract: A business specification is extracted so as to be represented by performing an analysis in a data item level by employing information which can be readily defined by a person who inputs business knowledge. While business functions and interfaces such as a series of screens corresponding to the business functions are employed as inputs, such a data item is extracted which is updated by employing an interface analysis and a program analysis. If a data item required for producing data which is updated in one business function is not inputted within this business function, the data item is defined as a preconditional condition item so as to be specified. If it is required that a business function for updating the preconditional condition item prior to the business function has been processed, a dependent relationship established between two pieces of the above-explained business is extracted so as to be represented.