This project presents an offline model-based testing approachof real-time systems using Ecdar. A test suite is generated thatcan be run locally on a system. Firstly, the timed input-outputautomaton was extended to contain test code in locations andedges. A new issue arose: how to handle clocks in the testcode. This was solved by using zones, and asserting that thesymbolic values are valid in the test code. Each test case in thetest suite is generated by reachability queries to each edge, andextending the trace to the next output edge. The approach wastested in three different case studies, and evaluated using PITmutation testing on the system. The case studies revealed thatthe approach was able to detect all the refinement violationsintroduced by mutants in the system under test. This project presents an offline model-based testing approachof real-time systems using Ecdar. A test suite is generated thatcan be run locally on a system. Firstly, the timed input-outputautomaton was extended to contain test code in locations andedges. A new issue arose: how to handle clocks in the testcode. This was solved by using zones, and asserting that thesymbolic values are valid in the test code. Each test case in thetest suite is generated by reachability queries to each edge, andextending the trace to the next output edge. The approach wastested in three different case studies, and evaluated using PITmutation testing on the system. The case studies revealed thatthe approach was able to detect all the refinement violationsintroduced by mutants in the system under test.