You take your weapons load out - say 4 9l, 4 SF. Then the number of AE, say 10 per sqn,say 8 sqn. 320 each.
Then look at the threat - say 300. Assume 2 shots each - 600. You appear to have a satisfactory weapon/target match.
For the second wave load out you have a working assumption of 10% attrition.
Required missiles to replenish those fired is now 2-2 for 72 aircraft. Ie 144 of each.
A buy of 500 each give a you full coverage for two waves. However your usage may not be 50-50 and exercise attacks are used to rebalance the numbers, say 60-40.
Then finally you make an assumption on length of c war and attrition. Your aircraft availability might run out as:
80 72 65 59 53 48 43 39 36 32 29 26 23 21 -
What screws everything is if you dont lose enough aircraft
for instance JP223 in GW 1 ran out before the aircraft whereas in WW 3 it was expected we would run out of aircraft.