System for determining whether screen displayed by program satisfies specification

It is determined whether a plurality of screens to be sequentially displayed by a process of a program satisfies a specification without executing this program. A system of the present invention stores a first schema prescribing a specification of a first screen, a second schema prescribing a specification of a second screen, and an event switching the display by program from the first screen to the second screen. First, a partial program executed in response to an event generated during displaying the screen satisfying the first schema is extracted from a program on the basis of the first schema and the event. Next, an intermediate program for calculating a set of screens being displayed in response to an event generated during displaying screens in a set of screens satisfying the first schema from this set is generated on the basis of the partial program. Next, it is determined that these screens satisfy a specification on condition that the first screen satisfies the first schema and a set of screens obtained by applying the intermediate program to the first schema satisfies the second schema.