In the safety engineering/mechanical engineering business this why you perform an FMEA: a Failure Mode and Effects Analysis. You list all that could possibly go wrong, how it could go and how it could go wrong. You assign a rating for the likelihood of it being detected, the severity if it does fail, and the frequency of occurrence or likely occurrence. You address each failure mode in order, based upon the product of the above three factors (detectability, severity, occurrence), with a mitigation strategy, only if you cannot entirely remove, or design away the risk.

You cannot (well you can) install automation controls on any old laptop or notebook. Good luck trying to show your smartphone to the insurance investigator!Our maintenance tablet had to be ruggedized to mil-spec, and had to have a rated e-stop button on it per BSI standards. We never used wireless control without being near a 'hard' e-stop, and always just for maintenance mode, no real runs with people around.

If you can get frustrated when your finger's sweaty with your touchscreen, imagine a 15 metric ton lift continuing to move at 100mm/s, because the touch screen on your smartphone still thinks your finger is holding the 'deadman' icon! Not to mention WiFi dropping, or your battery going dead.

I can only say this, since I have seen some hairy situations in my day.