I came across this today, it’s a formula to express “Anything that can go wrong, will“.

((U+C+I) x (10-S) / 20 x A x 1 / (1-sin(F/10))

U (urgency): 1 <= U <=9
C (complexity): 1 <= C <=9
I (importance): 1 <= I <=9
S (skill): 1 <= S <=9
F (frequency): 1 <= F <= 9

This equation was commissioned by British Gas.