Old 31st Aug 2018, 14:50
  #16 (permalink)  
DaveReidUK
 
Join Date: Jan 2008
Location: Reading, UK
Posts: 10,816
Originally Posted by WHBM View Post
This one always comes up, that the only route seen as an alternative to having every resource planned up to the theoretical hilt is to have DOUBLE the amount. Not a sensibly calculated contingency percentage but it has to be DOUBLE.
Not at all.

It's a fairly simple trade-off: the more slack you have in the form of spare resources, the fewer severely disrupted days you are likely to have. But to ensure no pear-shaped days at all, even doubling resources probably wouldn't be sufficient.

And of course the bean-counters aren't going to countenance that anyway.

Heathrow for example budgets for about a 300:50:15 balance - thats to say in terms of days per year:
300 where things go more-or-less as planned, with only minor hiccups
50 where the schedule is significantly disrupted but recoverable
15 where things get so bad the schedule can't be recovered (snow, severe ATC delays, etc)
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