A computer program automatically producing a system test specification adapted for real-life use of a computer system, such that the system's most important processing functions can be tested. An update record storage unit stores update records each including: a process identifier of a data updating process, the name of a dataset updated by that process, and an update timestamp. A function test data storage unit stores data of function tests for checking whether each module realizing operation steps of an operation flow satisfies specified requirements. An operation flow extractor creates a flow descriptor enumerating the names of datasets updated by a data updating process in chronological order. From the stored function test data, a system test generator compiles a system test description for each operation flow, which specifies a series of function tests in the same order as the operation steps constituting each operation flow.