The desc ties this to the completionTime property of a UCS PhysicalFsm object. This records when the current (or most recently run) FSM workflow on this server actually finished, letting an admin measure how long an operation like discovery or firmware association took, or confirm it hasn't completed at all if the field is still unset. Example: a blade that was just re-seated might show completionTime blank while its discovery FSM is mid-run, then populate a timestamp once discovery finishes.