It's time based, everything we do on the system is time coded, if there's a twenty minute gap in your output they will look further into it (I'm sure that's not for all staff but ones they know take the piss but they have to pretend to be fair). Most of the time they look and the notes/paperwork attached to a case and it makes sense why it took a while, if not then they will bring it up with someone. It works for me, doesn't feel like you're being watched all the time and no one is biting your head off for five minutes on your phone between cases, but at least the people I know do take the mick are to up their game.