+ 1 for that
and an suggestion for another system to measure your performance:
for departing airplanes: How close is the departure (until you hand over the plane to departure) of the plane to the reality? An example:
You get 100% if you:
push back within 2 Minutes, every minute later 10 % less
taxxing to the runway within 5 Minutes (dependig on the seize of the airport, in TIST of course less), 10% minus for every minute above that
and takeoff clearence / handover..
for incoming traffice the time the plane landed to the gate, full points for 5 Minutes (depending on the seize of the airport), every minute more 10% less
bad weather (snow etc... ) should extend the timeframe. If you crash a plane you get 0% for the day of course, security first!
Your personal performance should be visible in a chart, like today you got 85%. For the time in the game reale life should be an orientation