As someone who did a fair bit of (manual) scheduling with sizeable operators years ago, our starting point was to marry the available resources to sensible timetables for the passenger. This might mean a bit of stretching here or squeezing there but the passenger got an easily remembered timetable with reasonable reliability. With the coming of computerised systems, the system overtook the product and eventually we end up where we are now - a computer programmer with no feel for the product determines how it delivers and that is sacrosanct even if in reality it is nonsense. All that is needed is a skilled operating manager with the power and incentive to tweak the computer draft, and be prepared to defend those tweaks if challenged. Yes, on occasions that may break this 95%ile target, but no more than day to day traffic fluctuations will do anyway, and the user is offered a more sensible and memorable timetable into the bargain.