I'm out of the game now, but I will throw in a few comments from the past.
The BA pilot holding somewhere who said that he "couldn't hold for long as he was only carrying "Sword" fuel" (Sword of course referring to the computer flight plan).
Another aircraft chipped in with the words:
"He who lives by the sword...."
A BA Flight Manager who wrote to one of the captains asking why he had failed to carry minimum fuel on a recent sector. The reply simply said:
"What I carry...IS minimum fuel!"
For myself, I was always aware of the redundancy capability of the aircraft. We had more than one, indeed we had several, hydraulic, electric, air conditioning etc systems. Non of the beancounters ever suggested that we could remove some of them and save a fortune with the weight reduction. No one came out with figures suggesting that if we ran on just two hydraulic systems and operated x number of aircraft we would then save some y numbers of pounds every year.
And yet, bothers and sisters we have but one fuel system and that seems to be constantly under economic review. The concentration is always on landing fuel and never on the more important sector burn.
When that fuel system "fails", and it has "failed" on many occasions in the past, there is no backup. Not only will a lot of the lights go out but we will lose all the big dials and most of the comms.
Still makes me shiver to think about it!