Abstract: A method of updating a test description forming part of an automated test. The method includes obtaining a first time value associated with the sending of an instruction contained within the test description from the test computer to the system under test, obtaining a second time value associated with the receiving of an image comprising at least a portion of a GUI output of the system under test at the test computer, and using one or more processor devices to compare the first and second time values to determine timing information and update the test description using the timing information.