Can't help you with Southern Hemisphere stuff specifically, but for a generic calculation:
[list=1][*]Crew per pax - divide the number of pax by the number of crew (in each cabin or class), this gives you the number of pax to crew ratio. This in itself is a fairly meaningless measure, but is useful for comparing the different workloads on different aircraft types. For example, my company ratio would work out as: 757-200 @ 39.16 or with reduced crew @ 47.
[*]Time per pax - work out the flight time (airborne) and adjust for time lost when seatbelt signs are on, then divide by the crew ratio figure shown above. For example a 90 minute flight, less 20 minutes (10 minutes at each end for a secure cabin) gives 70 minutes, divided by my 47 pax allows just under a minute and a half per person. Again, a meaningless figure, but a quick and dirty way of measuring workload between different sector/crew combinations.[/list=1]
I'm sure some kind soul in QF will give you the heads up on the detail: As to interraction with customers, you get your 90 seconds, I guess. Of course, if I accidentally give one customer 100 seconds, it means someone else will only get 80 (who knows, they may think that a good thing?)
I just re-read this and realised what a sad old git I've become, using maths to quantify cabin services - Maybe I should get out more!
