This is just another Doug Taylor sililoquoy, but on-time performance doesn't mean squat. You can push a flight on time, it can sit at the gate for 30 minutes, do 30 minutes of holding and as long as it's no later than 14 minutes after the (padded) published arrival time, it's "on time".
And if you don't utilize reporting tools like ACARS, your OUT/OFF/IN/OUT times are up to the discretion of the reporter.
For example, one airline didn't have ACARS and they had a fantastic on-time statistic. Another airline that competed with the "king of on-time" (which invariably didn't use ACARS) decided to pull out the ACARS equipment and like magic, they started running on-time and their DOT statistics reflected such.
Sometimes on some flights, and this is with my own carrier including the one I worked with previous, we'd have a 1 hour, 18 minute flight time, but it was "blocked" at 2 hours and 30 minutes to account for ground ops screwups, holding and general gnashing of teeth. The DOT said "Woo hoo! It arrived on time!" even though almost an hour was eaten up by being #38 in line for takeoff, enroute holding and waiting for a pushback crew.
On-time performance means squat.