Our group of software systems design and testing investigates real-world problems and their solutions related to the development, testing and maintenance of software systems. This includes requirements specification, architectural design, construction (or programming), testing, deployment, and maintenance. The assembled group mostly focuses on software systems testing issues. Systems testing is relevant to the development of correct, long-lasting and consistent software systems. Various works of our group in the field of testing are related to the use of OCL constraints for testing, automated user interface testing, usability testing, symbolic testing. In our research we not only software engineering methods and tools, but also artificial intelligence methods. Artificial intelligence is mainly applied to user interface testing, where artificial intelligence automatically examines application screens detecting user interface problems. Group members organize testing-related conferences and other events, participate in testing-related projects.