5 ms·

Can't it cut wait times by infinity? For example, if the arrivals are at 1.1 per minute, and a teller processes 1 per minute.

by tome 2y ago

hinkley 2y ago
You've forgotten about banker's hours :)
- dylan604 2y ago
  There was a discussion not tool long ago about modern banks still with archaic practices. I have accounts at two different banks, and if I make a transfer request before 1:45PT, it is counted as same day. That makes no damn sense to me why that's a limitation at all today. It's not like a human needs to look at it, but even so, why the 1:45PT cutoff? Is it because it is 4:45ET? Then why not list it as that? And why does a banking computer system care about timezones or bankers' hours at all. It's all just mind boggling lame
  - hinkley 2y ago
    I know my father sometimes had to take 1 am phone calls because the insurance industry runs a lot of batch processing overnight, when the systems aren't competing with OLTP traffic. Banking software may be built the same way.
  - lmm 2y ago
    > Is it because it is 4:45ET? Then why not list it as that? Because a lot of their customers are too stupid to understand timezones.
    - dylan604 2y ago
      I guess that's saying more about the left coast customers then, right? as all of the customers from the other time zones have to do the conversion.
      - lmm 2y ago
        Well, if someone misunderstands and sends their payment by 1:45ET or 1:45CT, it's not a problem for the bank.
        hinkley 2y ago
        It’s never a problem for a bank, because they’re depend on late fees to hit their profit projections.
        lmm 2y ago
        A late fee that a customer quietly pays is a win. A late fee that a customer feels you screwed them over on and kicks up a fuss about can be more trouble than it's worth.
      - hinkley 2y ago
        If more businesses were based in Indiana we would understand this problem better. Gary Indiana is a population center on Lake Michigan, across the Illinois/Indiana border from the Chicago exurbs. They’ve elected to be in the same time zone as Illinois, while the rest of the state is in the same time zone as Ohio. And 1997-2006 was just a clusterfuck where another county joined with Gary, and a bunch of counties decided not to follow DST. I am not smart enough to know what time it is without asking a computer.
    - DiggyJohnson 2y ago
      This is just a rude guess and not relevant to the actual reason
      - lmm 2y ago
        Rude perhaps, but I think it very much is the actual reason. "If they listed it as 4:45ET their support costs would be higher" is perhaps the more polite way of putting it, but the meaning is not actually any different.
    - hinkley 2y ago
      I’m too stupid to understand time zones. Because everyone is too stupid to understand them at 2 am when alarms are going off. All backends should always be in UTC, even if your boss tells you we will “never” move our servers to another time zone. Because they’re going to buy or be bought by a company based in Chicago or New York or find a vertical so fat they want a second office there, or both. And then they will not remember promising you that you would never have to do a time zone migration. Why are you being so grumpy, just fix it?
  - chii 2y ago
    It's because when you do transfers, the banks will reconcile their accounts at the end of the day (e.g, if one bank deposits more to another, they will need to make up the difference with their own capital). These cutoff means banks have certainty about the transaction, as these reconciliation is batched, rather than real time.
    - hinkley 2y ago
      I think a better take on this may be credit cards. And an old classic article, “your coffee shop does not use two phase commit” https://ieeexplore.ieee.org/document/1407829 https://ieeexplore.ieee.org/document/1407829
SJC_Hacker 2y ago
Could be that, could also be the people taking a long time aren't at least causing a bottleneck (assuming there arent two of them at the same time). So you have this situation like this: first person takes 10 minutes, while there are 9 waiting in line that take only one minute a piece. With one teller, average wait time is ~15 minutes. With two tellers, its now ~5 minutes. Which is why it is highly annoying when there's only one worker at the coffee stand, and there's always this one jerk at the front of the queue who orders a latte when you just want a coffee. With two workers, the people who just want coffee won't have to wait 15 minutes for the lattee people And I've also noticed a social effect, when people wait a long time it seems to reinforce how they perceive the eventual serviced, that is, they want more out of the interaction, so take longer. Which makes it the situation even worse
- lostlogin 2y ago
  > there's always this one jerk at the front of the queue Here in the espresso world, that’s not so bad. But the ‘vanilla oat milk decaf, and also a hot muffin with butter’ is tedious. There is a roaster in Auckland that’s been there since the ‘80s. On the counter it says ‘espresso, flat white or fuck off’. Clear and concise. I like it. https://millerscoffee.co.nz/ https://millerscoffee.co.nz/
  - gerdesj 2y ago
    "On the counter it says ‘espresso, flat white or fuck off’" Sounds a bit pretentious to me. I generally order a coffee, no milk ... ta.
    - pimlottc 2y ago
      Try ordering a “just a cup of coffee” in AU/NZ and they will look at you with a blank expression. Espresso is the norm there.
    - DiggyJohnson 2y ago
      Presumably whoever wrote that sign anticipates this criticism
hiAndrewQuinn 2y ago
The Poisson process is a random distribution. Just because its average is 1.1 per minute doesn't mean you can't have 2 people show up at virtually the same time, it's just pretty rare. Or there's like a 10^-100 chance a million people show up at the same second, etc etc. You'll always have some nonzero average queuing time if you calculate it across the whole distribution for that reason.

Can't it cut wait times by infinity? For example, if the arrivals are at 1.1 per minute, and a teller processes 1 per minute.

by tome 2y ago

Can't it cut wait times by infinity? For example, if the arrivals are at 1.1 per minute, and a teller processes 1 per minute.

hinkley 2y ago

You've forgotten about banker's hours :)

dylan604 2y ago
There was a discussion not tool long ago about modern banks still with archaic practices. I have accounts at two different banks, and if I make a transfer request before 1:45PT, it is counted as same day. That makes no damn sense to me why that's a limitation at all today. It's not like a human needs to look at it, but even so, why the 1:45PT cutoff? Is it because it is 4:45ET? Then why not list it as that? And why does a banking computer system care about timezones or bankers' hours at all. It's all just mind boggling lame
- hinkley 2y ago
  I know my father sometimes had to take 1 am phone calls because the insurance industry runs a lot of batch processing overnight, when the systems aren't competing with OLTP traffic. Banking software may be built the same way.
- lmm 2y ago
  > Is it because it is 4:45ET? Then why not list it as that? Because a lot of their customers are too stupid to understand timezones.
  - dylan604 2y ago
    I guess that's saying more about the left coast customers then, right? as all of the customers from the other time zones have to do the conversion.
    - lmm 2y ago
      Well, if someone misunderstands and sends their payment by 1:45ET or 1:45CT, it's not a problem for the bank.
      - hinkley 2y ago
        It’s never a problem for a bank, because they’re depend on late fees to hit their profit projections.
        lmm 2y ago
        A late fee that a customer quietly pays is a win. A late fee that a customer feels you screwed them over on and kicks up a fuss about can be more trouble than it's worth.
    - hinkley 2y ago
      If more businesses were based in Indiana we would understand this problem better. Gary Indiana is a population center on Lake Michigan, across the Illinois/Indiana border from the Chicago exurbs. They’ve elected to be in the same time zone as Illinois, while the rest of the state is in the same time zone as Ohio. And 1997-2006 was just a clusterfuck where another county joined with Gary, and a bunch of counties decided not to follow DST. I am not smart enough to know what time it is without asking a computer.
  - DiggyJohnson 2y ago
    This is just a rude guess and not relevant to the actual reason
    - lmm 2y ago
      Rude perhaps, but I think it very much is the actual reason. "If they listed it as 4:45ET their support costs would be higher" is perhaps the more polite way of putting it, but the meaning is not actually any different.
  - hinkley 2y ago
    I’m too stupid to understand time zones. Because everyone is too stupid to understand them at 2 am when alarms are going off. All backends should always be in UTC, even if your boss tells you we will “never” move our servers to another time zone. Because they’re going to buy or be bought by a company based in Chicago or New York or find a vertical so fat they want a second office there, or both. And then they will not remember promising you that you would never have to do a time zone migration. Why are you being so grumpy, just fix it?
- chii 2y ago
  It's because when you do transfers, the banks will reconcile their accounts at the end of the day (e.g, if one bank deposits more to another, they will need to make up the difference with their own capital). These cutoff means banks have certainty about the transaction, as these reconciliation is batched, rather than real time.
  - hinkley 2y ago
    I think a better take on this may be credit cards. And an old classic article, “your coffee shop does not use two phase commit” https://ieeexplore.ieee.org/document/1407829 https://ieeexplore.ieee.org/document/1407829

SJC_Hacker 2y ago

Could be that, could also be the people taking a long time aren't at least causing a bottleneck (assuming there arent two of them at the same time). So you have this situation like this: first person takes 10 minutes, while there are 9 waiting in line that take only one minute a piece. With one teller, average wait time is ~15 minutes. With two tellers, its now ~5 minutes. Which is why it is highly annoying when there's only one worker at the coffee stand, and there's always this one jerk at the front of the queue who orders a latte when you just want a coffee. With two workers, the people who just want coffee won't have to wait 15 minutes for the lattee people And I've also noticed a social effect, when people wait a long time it seems to reinforce how they perceive the eventual serviced, that is, they want more out of the interaction, so take longer. Which makes it the situation even worse

lostlogin 2y ago
> there's always this one jerk at the front of the queue Here in the espresso world, that’s not so bad. But the ‘vanilla oat milk decaf, and also a hot muffin with butter’ is tedious. There is a roaster in Auckland that’s been there since the ‘80s. On the counter it says ‘espresso, flat white or fuck off’. Clear and concise. I like it. https://millerscoffee.co.nz/ https://millerscoffee.co.nz/
- gerdesj 2y ago
  "On the counter it says ‘espresso, flat white or fuck off’" Sounds a bit pretentious to me. I generally order a coffee, no milk ... ta.
  - pimlottc 2y ago
    Try ordering a “just a cup of coffee” in AU/NZ and they will look at you with a blank expression. Espresso is the norm there.
  - DiggyJohnson 2y ago
    Presumably whoever wrote that sign anticipates this criticism

hiAndrewQuinn 2y ago

The Poisson process is a random distribution. Just because its average is 1.1 per minute doesn't mean you can't have 2 people show up at virtually the same time, it's just pretty rare. Or there's like a 10^-100 chance a million people show up at the same second, etc etc. You'll always have some nonzero average queuing time if you calculate it across the whole distribution for that reason.