Abstract: A method, apparatus, and article of manufacture for a computer-implemented random reliability engine for testing distributed computer environments. The random reliability engine performs reliability testing of applications in a distributed environment. The random reliability engine simulates a user who is invoking various commands in various documents that are open in the distributed environment. The random reliability engine is a random rule based engine that generates random sequences of commands on documents. The random reliability engine generates these sequences for a fixed amount of time. When these sequences are successfully executed within the fixed amount of time, the random reliability engine determines that the distributed environment is reliable. Moreover, the random reliability engine can be implemented as a graphical user interface test script that is executed by a graphical user interface driver.