Pondering reservation numbers

[theredwoodguy]

This is actually an interesting question...

 

If you figure that there are about (currently) 38k cabins spread over 25 ships and something like 1500 sailings in a year across the fleet -- figuring in that the average cruise length is probably a week with some shorter ones interspersed.

 

By those numbers there would be 57m reservations per year! The current reservation numbers are 7 digit numbers so the range would be 10m...

 

So, on average a reservation number is used 5.7 times a year. :eek:

 

And the reality is that there are probably some numbers that get used more frequently. I've got reservations in 2017 so those won't go back into the pool until I've gone on the cruise. And one of those was from a several year old NCC so it'll have been out of the pool for about 5 years by the time it gets back in.

 

How many cruises do I need to take to get the reservation number 0000000 or 9999999? I'm sure someone with a better background in statistics could figure it out. :D

 

This is the difference in "Thinking about it" and "Thinking it through"! Very good post Tahqa!!

[tahqa]

I underestimated the number of cabins/ships/sailings! I think this is pointing to the fact that the real "unique key" for the reservation is the combination of the reservation number, your surname and sailing date, and possibly ship as well which explains why they ask for these things at various stages, instead of just the reservation number alone.

 

In reflection I suspect that this is correct. It appears that reservation numbers are not necessarily unique... Whenever I call to service my reservation they always ask my name... I thought this was to verify that I was the owner of the reservation but it could also be that they are given a list of reservations when they key in the number and have to ask my name to select the appropriate reservation.

 

Also, numbers aren't necessarily 7 digits. One of my friends has a 6 digit reservation number.

 

Regardless, even if numbers could be between 1 and 7 digits long they wouldn't have enough. That would still be only 11111110 possibilities. :eek:

[The_Big_M]

Also, numbers aren't necessarily 7 digits. One of my friends has a 6 digit reservation number.

 

Regardless, even if numbers could be between 1 and 7 digits long they wouldn't have enough. That would still be only 11111110 possibilities. :eek:

 

Those are actually the reservation numbers just said without the 0 at the front i.e. you could say reservation 603103, or 0603103. If they actually made two different numbers like that, it would be too confusing!

 

So the actual total is still 10,000,000 i.e. those above are in the range under a million.

[yj_eugene]

If you figure that there are about (currently) 38k cabins spread over 25 ships and something like 1500 sailings in a year across the fleet -- figuring in that the average cruise length is probably a week with some shorter ones interspersed. By those numbers there would be 57m reservations per year!

 

1500 sailings * (38k cabins / 25 ships) = 2.28m reservations per year. With 10m reservation numbers, that takes 10m/2.28m or about 4.4 years to cycle through them. If each reservation uses 2.5 numbers each time, per the TA info in an earlier post, then still each number takes 4.4/2.5 = 1.76 years to recycle. Even allowing for reservations that span multiple years, stockpiled NCC's, holds that expire, numbers that might not be issued (0000666 :eek:) etc, I'd guess that numbers rarely if ever would be reused within a year.

[tahqa]

1500 sailings * (38k cabins / 25 ships) = 2.28m reservations per year. With 10m reservation numbers, that takes 10m/2.28m or about 4.4 years to cycle through them. If each reservation uses 2.5 numbers each time, per the TA info in an earlier post, then still each number takes 4.4/2.5 = 1.76 years to recycle. Even allowing for reservations that span multiple years, stockpiled NCC's, holds that expire, numbers that might not be issued (0000666 :eek:) etc, I'd guess that numbers rarely if ever would be reused within a year.

 

You're right, the final number should have been divided by the number of ships. Each cabin does an average (across the fleet) of 55 sailings a year.

 

I did a better tally of cabins and sailings and came up with 2.13m reservations per year. :o

[Thoie]

The other thing is that with a 7 digit reservation number, that only allows 10m combinations - they must cycle through them pretty fast? At a rough guess, one of the Oasis class ships could probably go through nearly 150k reservations a year, and that's just one ship. I'd take a guess that they have to reuse numbers about every 5 years.

 

I did a better tally of cabins and sailings and came up with 2.13m reservations per year.

 

My initial guesstimate of a 5 year recycling wasn't too far off then :)

[tahqa]

The other thing is that with a 7 digit reservation number, that only allows 10m combinations - they must cycle through them pretty fast? At a rough guess, one of the Oasis class ships could probably go through nearly 150k reservations a year, and that's just one ship. I'd take a guess that they have to reuse numbers about every 5 years.

 

My initial guesstimate of a 5 year recycling wasn't too far off then :)

 

Not only that... but my back of the envelope calculations put Oasis at about 141k reservations per year, so you were pretty close there as well. :)