5 ms·

Why would you ever reuse an identifier like that? Is there some kind of material cost associated with a new identifier?

magicalhippo 4y ago
This is what we've never understood. Trying to ask why is almost always futile, the people who're there now never knows. I suspect it's often some legacy stuff, like a certain system only had 6 chars available for the reference, and so that's how they ended up working around it and nobody realized that limitation no longer exists. But yeah, does not make much sense to us either.
- namdnay 4y ago
  Just like passenger name records - 6 characters for legacy reasons, so they’re constantly recycled
- martyvis 4y ago
  Is it a fully computerised B2B system? I mean when I order some patch cables for a project, I do it via a web shop and pay with my corporate credit card. The vendor generates an order number but also asks me for customer purchase order reference. I just make something up that might have my initials and date and a serial like "MV-20220723-1". Others may not be so methodical.
  - magicalhippo 4y ago
    Yeah this is B2B, so should be computer generated. Then again, who knows what goes on behind the scenes...
- deleted 4y ago
  [deleted]
- david_p 4y ago
  This reminds me of a project I was remotely involved with: Airbus having to handle an aircraft order number above 5 digits as they were delivering their 10’000th aircraft to a customer. This was a multi year project where we had to deliver software used to map risk and impact across the whole company. Imagine the costs. source: https://www.flightglobal.com/airlines/a320neo-line-adapts-to-five-digits-for-msn10000-delivery/140541.article https://www.flightglobal.com/airlines/a320neo-line-adapts-to...
  - magicalhippo 4y ago
    Yeah I mean I also get that aspect. We integrate with many systems, we have 18 different integrations with one of our larger customers, and we're just a small piece of the puzzle. Would likely be super costly just to figure out which, if any, of the systems that would have to change.
hughes 4y ago
Even the USPS reuses tracking numbers. I had a package show as "delivered" before it even shipped once, because it received a recycled tracking number.
- hgomersall 4y ago
  I don't even reuse references inside a single running instance of software. Using u64 you can generate billions a second and still not run out for hundreds of years.
  - rahimnathwani 4y ago
    Right, but u64 is kind of long for something you might want to read over the phone, or enter using DTMF tones.
    - JonathonW 4y ago
      USPS tracking numbers are at least 22 digits long (depending on shipping method; some can be 27); I don’t think ease of data entry was a priority for them. 22 digits and they somehow still manage to reuse tracking numbers. 10^22 (or 10^20, if we assume some encoding overhead) valid numbers should be able to uniquely identify a lot of mail.
      - HPsquared 4y ago
        They probably encode information in the code itself then, perhaps source/destination or similar. Perhaps to allow "offline" operations?
      - thejosh 4y ago
        A lot of the first digits are actually used for parsing. It's not a fully unique number. USPS labels (and other labels from other couriers) are an incredibly fascinating subject you would never care about until you work in the industry.
      - jsjohnst 4y ago
thih9 4y ago
They might need a new type of identifier to guarantee uniqueness. And there might be cost associated with updating the system (workflows, databases, scanners, training, etc) to deal with new type of identifiers.
rolandog 4y ago
I'm thinking either production or the warehouse still uses manual stamping of lot (or shipment) numbers with those auto-increment stamps... The number is then captured by hand into a system somewhere. The system worked fine when production was X times smaller, but no attention has been paid to it since it was first designed.
liotier 4y ago
Some legacy identifiers come in fixed length fields, insufficient for contemporary usage. I know a company where some identifier should have been lengthened long ago, but that would impact a couple hundred systems (and by system I mean whole applications, front and back) - so they keep plodding on with what they have and yes, it is a drag on operations and it causes endless hacks.
deleted 4y ago
[deleted]
LorenPechtel 4y ago
I have worked for a company that reused order-tracking identifiers. The reason was mechanical: The more digits in the identifier the bigger the barcode on the shipping label. A non-issue with 2D barcodes but back then it was an issue.
mathattack 4y ago
In some cases it’s a flag that there’s a mainframe underneath that people are afraid to touch with the number of digits fixed to save memory. So many other legacy systems assume the field is fixed that you can’t add digits. Companies then look and say, “We can spend tens of millions of dollars to fix this, or we can spend the money on advertising and compensation, and just deal with the issues that come with reusing numbers”
vkk8 4y ago
Totally different context, but at my company, they started reusing some IDs that are supposed to be unique because they ran out of them and the old-as-fuck computer systems can't handle longer IDs.
notoriousjpg 4y ago
Many airlines reuse your booking reference number too

This is what we've never understood. Trying to ask why is almost always futile, the people who're there now never knows. I suspect it's often some legacy stuff, like a certain system only had 6 chars available for the reference, and so that's how they ended up working around it and nobody realized that limitation no longer exists. But yeah, does not make much sense to us either.

namdnay 4y ago
Just like passenger name records - 6 characters for legacy reasons, so they’re constantly recycled
martyvis 4y ago
Is it a fully computerised B2B system? I mean when I order some patch cables for a project, I do it via a web shop and pay with my corporate credit card. The vendor generates an order number but also asks me for customer purchase order reference. I just make something up that might have my initials and date and a serial like "MV-20220723-1". Others may not be so methodical.
- magicalhippo 4y ago
  Yeah this is B2B, so should be computer generated. Then again, who knows what goes on behind the scenes...
deleted 4y ago
[deleted]
david_p 4y ago
This reminds me of a project I was remotely involved with: Airbus having to handle an aircraft order number above 5 digits as they were delivering their 10’000th aircraft to a customer. This was a multi year project where we had to deliver software used to map risk and impact across the whole company. Imagine the costs. source: https://www.flightglobal.com/airlines/a320neo-line-adapts-to-five-digits-for-msn10000-delivery/140541.article https://www.flightglobal.com/airlines/a320neo-line-adapts-to...
- magicalhippo 4y ago
  Yeah I mean I also get that aspect. We integrate with many systems, we have 18 different integrations with one of our larger customers, and we're just a small piece of the puzzle. Would likely be super costly just to figure out which, if any, of the systems that would have to change.

hughes 4y ago

Even the USPS reuses tracking numbers. I had a package show as "delivered" before it even shipped once, because it received a recycled tracking number.

hgomersall 4y ago
I don't even reuse references inside a single running instance of software. Using u64 you can generate billions a second and still not run out for hundreds of years.
- rahimnathwani 4y ago
  Right, but u64 is kind of long for something you might want to read over the phone, or enter using DTMF tones.
  - JonathonW 4y ago
    USPS tracking numbers are at least 22 digits long (depending on shipping method; some can be 27); I don’t think ease of data entry was a priority for them. 22 digits and they somehow still manage to reuse tracking numbers. 10^22 (or 10^20, if we assume some encoding overhead) valid numbers should be able to uniquely identify a lot of mail.
    - HPsquared 4y ago
      They probably encode information in the code itself then, perhaps source/destination or similar. Perhaps to allow "offline" operations?
    - thejosh 4y ago
      A lot of the first digits are actually used for parsing. It's not a fully unique number. USPS labels (and other labels from other couriers) are an incredibly fascinating subject you would never care about until you work in the industry.
    - jsjohnst 4y ago

thih9 4y ago

They might need a new type of identifier to guarantee uniqueness. And there might be cost associated with updating the system (workflows, databases, scanners, training, etc) to deal with new type of identifiers.

rolandog 4y ago

I'm thinking either production or the warehouse still uses manual stamping of lot (or shipment) numbers with those auto-increment stamps... The number is then captured by hand into a system somewhere. The system worked fine when production was X times smaller, but no attention has been paid to it since it was first designed.

liotier 4y ago

Some legacy identifiers come in fixed length fields, insufficient for contemporary usage. I know a company where some identifier should have been lengthened long ago, but that would impact a couple hundred systems (and by system I mean whole applications, front and back) - so they keep plodding on with what they have and yes, it is a drag on operations and it causes endless hacks.

deleted 4y ago

[deleted]

LorenPechtel 4y ago

I have worked for a company that reused order-tracking identifiers. The reason was mechanical: The more digits in the identifier the bigger the barcode on the shipping label. A non-issue with 2D barcodes but back then it was an issue.

mathattack 4y ago

In some cases it’s a flag that there’s a mainframe underneath that people are afraid to touch with the number of digits fixed to save memory. So many other legacy systems assume the field is fixed that you can’t add digits. Companies then look and say, “We can spend tens of millions of dollars to fix this, or we can spend the money on advertising and compensation, and just deal with the issues that come with reusing numbers”

vkk8 4y ago

Totally different context, but at my company, they started reusing some IDs that are supposed to be unique because they ran out of them and the old-as-fuck computer systems can't handle longer IDs.

notoriousjpg 4y ago

Many airlines reuse your booking reference number too