Glad you gained time.
The flaw is that an average day is compared to a specific day, in time study. Allowances at UPS can hold the driver liable for not meeting the average standards on a daily basis.
An average, is just an average.
The best analogy I can think of is the life expectancy of the average male.
The average is 77yrs, but the kicker is that the majority of men do not die at that age.
If UPS calls a driver to task for not meeting the average on a daily basis, then they are flawed in their logic.
Apply averages to averages.
Simply put,
Average the performance of the driver over the years of service to the average expected by UPS on a daily basis.(this will never happen)
The variables of a single day will always differ from the average day.
Sorry for my rant, but I live in the real world.