Disclosed is a novel computer implemented system, on demand service, computer program product and a method for fault-localization techniques that apply statistical analyses to execution data gathered from multiple tests. The present invention determines the fault-localization effectiveness of test suites generated according to several test-generation techniques based on combined concrete and symbolic (concolic) execution. These techniques are evaluated by applying the Ochiai fault-localization technique to generated test suites in order to localize 35 faults in four PHPWeb applications. The results show that the test-generation techniques under consideration produce test suites with similar high fault-localization effectiveness, when given a large time budget.