Tracking starts automatically when you move to the next test in the wizard. However, if a tester takes a short break, this break time is later tracked as well. After saving the result, the time can also no longer be adjusted.
Last time after a test in a test run the PC was shut down for the weekend. Monday the next test was made - this one has a tracked time of over 75h and it can't be adjusted anymore.
Unfortunately, this is extremely unattractive for the statistics.