1. A method for performing regression tests in a state-dependent data processing system where data are processed by means of at least one function having a signature of defined parameters and corresponding values, and wherein a regression test is performed using at least one pre-recorded function test case and at least one pre-determined set of test data corresponding to said signature and being used to execute said at least one pre-recorded function test case, said method comprising the step of adapting said at least one function test case and/or said at least one set of test data to any changed signatures caused by a state transition of said data processing system.