Combat Repair

Because when your combat is broken, you won't have a happy face.

So as to forestall arguments, combat repair attempts end when you a) FTL out of the system or b) send in the marines to mop up after your successful action. Scotty has to go and have a lie down, and the deputy engineers work to rule without his inspiring leadership.

Because otherwise you would claim that you'd spent a whole week making combat repair rolls as you travelled around. I shouldn't have to explain that I'm not remotely patient enough to put up with that.