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Pondering reservation numbers

Thoie

By Thoie,
in Royal Caribbean International

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Thoie

Thoie

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This is completely trivial - just throwing it out there to see if anyone knows a good reason.

 

My next cruise in October was booked last January and has a reservation number starting 40. I booked two cruises together a few days ago, and they have reservation numbers starting with 37 and 35. It would make logical sense to me if the reservations numbers were assigned in order, but they obviously aren't.

 

The only thing I can think of is that reservation numbers are randomly generated at the start of each booking, in order to stop people "guessing" at reservation numbers (though I don't know what good that would do them without a matching surname).

 

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.

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nolesrule

nolesrule

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When you call them and give the res no, they get you to confirm ship and date. I wonder if some of that Is to check the number is right but maybe they have more than one with the number

 

 

Well, what happens if you get it wrong? Do they let you guess every ship and date until you pick the correct one?

 

Generally, confirming 3 data points is a security best practice.

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kruzerci

kruzerci

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When you call them and give the res no, they get you to confirm ship and date. I wonder if some of that Is to check the number is right but maybe they have more than one with the number

 

 

I'm sure they probably reuse numbers after the sailing is complete but I highly doubt they would use it more than once on an open booking.

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JulieRose

JulieRose

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My mother and I booked the same ship less than 24 hours from one another and my reservation (made first) started with a 17, my mothers begins with a 19. The cruise on a different ship that we booked 2 weeks earlier starts with 58.

 

IDK what (if anything) all of that means but this has been my recent experience.

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Thetrail

Thetrail

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This is completely trivial - just throwing it out there to see if anyone knows a good reason.

 

My next cruise in October was booked last January and has a reservation number starting 40. I booked two cruises together a few days ago, and they have reservation numbers starting with 37 and 35. It would make logical sense to me if the reservations numbers were assigned in order, but they obviously aren't.

 

The only thing I can think of is that reservation numbers are randomly generated at the start of each booking, in order to stop people "guessing" at reservation numbers (though I don't know what good that would do them without a matching surname).

 

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.

All I can say is WOW....:D
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Thoie

Thoie

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Does it really matter? SMH!

 

Not in the slightest - that's what "trivial" means. I was just curious to see if anyone else had spotted any rhyme or reason, or had noticed, or cared. You obviously don't.

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BillOh Holiday Sharing Rare

BillOh

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I think you all need a cruise!:D

 

I've wondered the same thing as the OP, but rarely have more than one cruise booked at a time. I was using my Wii Fit today and its limited brain can't grasp that I have been using it longer than 2000 days that is its max. I do know Royal recycles reservations numbers, the largest number must be big enough that duplications don't happen.

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KiwiGal117

KiwiGal117

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Our TA told us that each cabin is reserved, on average 2 and a half times before a sailing, so they would cycle through numbers that much faster. Agree, it's trivial, but more fun to think about than say, work and bills.

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tahqa

tahqa

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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

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Thoie

Thoie

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Maybe certain prefixes are assigned to each ship so they can tell which ship you are on by using that.

 

They would have to recycle numbers or it would be a lot larger number than 7 digits.

 

Two of the reservations I mentioned in the first post are on the same ship B2B, so it's not that.

 

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.

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.

 

It's obviously working for them, but it's not how I'd set it up :) The simple addition of alphabetical characters in the reservation number (like airline PNRs) would make a 7 character reservation id look something like 123ab45, and would give them over 78 billion IDs before they needed to recycle - or 1,300 years between reusing the same numbers :)

 

 

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

 

Smart arse answer - if the reservation numbers are assigned randomly each time you make a new booking, then to guarantee you get one of those numbers, you'd need to make 9,999,998 reservations :D

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HeidiHo

HeidiHo

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They do recycle numbers. I was saw a really short number.I don't remember how many digits (maybe 3-5 numbers) but whenever I called RCI and gave them the booking number I would read it off and then would be silence because they would be waiting for me to finish reading off the number. Even they were surprised it was so short and that was when I was told that they do recycle them.

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Thoie

Thoie

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The number of combinations is orders of magnitude greater than 10 million, since you are dealing with a factorial of 10

 

I've forgotten my secondary school maths. I was calculating it as 10 possible digits (0-9), and 7 possible unrelated places, so 10^7 = 10m.

 

Because each number in the sequence is unrelated to the number already picked, each "place" is independent. If you said a reservation number could only be 2 digits, made up of the digits 1 or 2, then your possible outcomes are

11,12,21,22 - 4 choices. Which is 2^2. If we said it could be 3 digits, still only using 1 or 2, then that would be 2^3=8

 

111,112,121,122,222,211,212,221.

 

So 10 million is correct (10^7).

 

 

10! (factorial 10) only equals 3.6m

 

We use factorials when the numbers are "used up" once they've been picked once. So if our reservation numbers are 7 digits long, made up of 0-9, but each digit can only be used once, then we'd be looking at 10C7 =

 

10!/(7! x 3!) = 10x9x8/3x2x1 = 5x3x8 = 120

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Thoie

Thoie

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If they are random and recycled, there is no guarantee you'd ever get a specific number.

 

Even if he had 9,999,998 open reservations at once? Of course, that would be very selfish of him, as there'd be no more cruises available for the rest of us :)

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