Comment by gmueckl

"Responding in time" here means meeting a hard deadline under any circumstances, no matter what else may be going on simultaneously. The counterintuitive part is that this about worst case, not best case or average case. So you might not want a fancy algorithm in that code path that has insanely good average runtime, but a tiny chance to blow up, but rather one that is slower on average, but has tight bounded worst case performance.

Example: you'd probably want the airbags in your car to fire precisely at the right time to catch you and keep you safe rather than blow up in your face too late and give you a nasty neck injury in addition to the other injuries you'll likely get in a hard enough crash.