A method for eliminating ambiguity and incorrectness of the specification determined in a requirement defining phase in developing an information system, and systematically verifying whether an automatically executed test scenario agrees with the original requirements in a functional testing phase, includes extracting an input variable, an output variable, and the respective types of the variables from a specification file in screens; extracting screen-transition information from a composite functional specification containing specifications in screens; and executing the following processes from the top for each screen that appears in screen transition. For the input variable, the apparatus generates a test script indicative of an action (clicking or a character set) corresponding to an object associated with the input variable. For the output variable, the apparatus generates a test script for comparing text information displayed on a screen with an expected value determined from the output variable.