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Scientifically, You Are Likely In the Slowest Line

timothy posted more than 3 years ago | from the why-to-shop-online dept.

Math 464

MojoKid writes "As you wait in the checkout line for the holidays, your observation is most likely correct. That other line is moving faster than yours. That's what Bill Hammack (the Engineer Guy), from the Department of Chemical and Biomolecular Engineering at the University of Illinois — Urbana proves in this video. Ironically, the most efficient set-up is to have one line feed into several cashiers. This is because if any one line slows because of an issue, the entry queue continues to have customers reach check-out optimally. However, this is also perceived by customers as the least efficient, psychologically."

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Costco (2)

TastelessGarbage (598415) | more than 3 years ago | (#34656286)

Please, please, someone forward this to Jim Sinegal.

Re:Costco (5, Insightful)

jschen (1249578) | more than 3 years ago | (#34656508)

Let's think about this a bit first. At a place like Costco, you may be trying to feed 20+ registers at a busy time. In terms of average wait time, it's better to have each line constantly full rather than to have someone have to move over to a register and start putting things up on the conveyor belt only after someone else cleared said register. One solution to this is that you specify have exactly one customer waiting behind each register, starting to load goods onto the conveyor belt. First of all, you now have the exact unfairness issue that multiple lines causes since one person might be behind someone with one item, and another behind someone with dozens of items. Might as well let them pick lines since you have the same result anyways, and don't need as much space dedicated to people forming a long line. If you still want to consider a single line, what about those far away stations (there must be at least one register 10 stations away or more)? And what if someone at one of those far away locations only has one or two items? Maybe we should switch to two customers behind each register before forming a big line? And how does a single line affect traffic in the store when you have 40+ people jamming up your main aisle on one side? Maybe we should have a line on each side? Or maybe it's best to let the customers sort through the situation, and just focus on having all open registers used to capacity, as currently is done.

Re:Costco (1)

ChrisMaple (607946) | more than 3 years ago | (#34656634)

Single queues have further disadvantages. It takes time to get to the newly opened register. About 1 customer in 5 is a doofus too slow to respond to the opening until someone starts poking him. Some stores even have to appoint a person (sometimes two) to point out the opening and get the head of the line moving (thus adding to overhead and the price the customer pays).

Single queues to multiple checkouts work well when the number of checkouts is small and they're close together, and it especially helps if there's a tendency for occasional customers to take much longer than the average. (This happens when there are price checks, arguments over prices, or [in airports] itinerary changes.) It isn't a reasonable option for a WalMart with 40 registers.

Re:Costco (0)

commodore64_love (1445365) | more than 3 years ago | (#34656638)

Woah.

Yes you're right that having the second "waiting" person fill the conveyor belt with his food saves time, rather than have them standing back in the Single line queue while the belt sits empty. That's probably why stores continue to have separate lines, but at a bank or 7/11 that would not be an issue and the single line would be more efficient.

This week I discovered a benefit of the "self checkout" line. Free food. I scanned my ~20 meals of frozen packages, but one of them jammed the eye sensor for some reason. The machine credited $2 to my account but the item was still sitting ten feet away next to the bags. Rather than go retrieve it I just shrugged my shoulders & scanned the next item.

Apparently these things need some work. The store is saving about $7/hour by eliminating a clerk but if they give-away food then they will be losing in the long term.

Hmm (1)

windcask (1795642) | more than 3 years ago | (#34656298)

That, or it's a more efficient use of space to have displays and inventory running down the center of the store, rather than a huge empty lane leading into a tree of registers.

What's so new about single line queue? (3, Informative)

BLToday (1777712) | more than 3 years ago | (#34656302)

I thought we've verify the efficiency of single line queue for many years.

Re:What's so new about single line queue? (5, Informative)

Random BedHead Ed (602081) | more than 3 years ago | (#34656338)

This is the norm in Britain. And it works. But trying to get people to do this in the States is like pulling teeth.

Re:What's so new about single line queue? (1)

blackraven14250 (902843) | more than 3 years ago | (#34656518)

Every post office and bank in my area does this, along with book stores, most of the eateries, airports, and nearly anywhere else. I hardly ever see multiple lines, regardless as to venue, in the last few years - in the states.

Re:What's so new about single line queue? (1)

somersault (912633) | more than 3 years ago | (#34656526)

Yeah we do this on self checkouts here. It seems obvious that it's the most efficient method.

Re:What's so new about single line queue? (1)

mysidia (191772) | more than 3 years ago | (#34656652)

Yeah we do this on self checkouts here. It seems obvious that it's the most efficient method.

I think the analysis is incomplete for the supermarket situation however.

Consider the case where you have a very large number of people going through the system and 10 or 11 registers.

Consider how much floor space it takes to have 10 or 11 registers.

Consider that a "single queue" to go to all the registers has to live somewhere.

That will mean that there is some non-trivial distance to be travelled from the queue to the next available register.

Eventually the non-trivial distance, means a closer register gets freed up before the shopper can reach the farthest register.

The result.... as the distance the shopper's wagon has to be pushed to reach the farthest register increases, the less efficient the usage of that farthest register, with there always being a free register that is closer, it will never be used.

Re:What's so new about single line queue? (1)

DrLang21 (900992) | more than 3 years ago | (#34656790)

Consider how much floor space it takes to have 10 or 11 registers.

Not much at all for a department store (because it usually requires very little counter space). But lets consider Costco as the worst case scenario. Simply breakup the system into 2 or 3 queues to make up for customers failing to pay attention to all of the registers.

Re:What's so new about single line queue? (2)

ddrichardson (869910) | more than 3 years ago | (#34656546)

Some places yes but I wouldn't say its "the norm" - certainly none of the supermarkets does it and that's where it pisses me off. Stand for 15 minutes in a queue only for someone to open a new till for someone who's hasn't waited at all.

I think as a nation, Britain has a real etiquette about queuing and I know I feel a real injustice when someone gets to skip it.

Re:What's so new about single line queue? (1)

mysidia (191772) | more than 3 years ago | (#34656596)

Some places yes but I wouldn't say its "the norm" - certainly none of the supermarkets does it and that's where it pisses me off. Stand for 15 minutes in a queue only for someone to open a new till for someone who's hasn't waited at all.

I bet that one person who doesn't have to wait thinks that method is the most efficient.

Keep shopping until an opportunity comes up to get in a short line and be done with it; while the sheep and inattentive continue to wait in line for long periods of time, which means they're not interfering with your ability to get checked out and done quickly.

Re:What's so new about single line queue? (1)

blackraven14250 (902843) | more than 3 years ago | (#34656782)

Couldn't you also be considered a sheep, for deciding to buy impulsively while you walk around the store aimlessly?

Re:What's so new about single line queue? (1)

commodore64_love (1445365) | more than 3 years ago | (#34656682)

"Nobody knows how to queue better than a Briton!" - Arthur Dent. 15 mins? I usually stand less than 5 at the US grocery stores.

I usually see a chaotic oscillation (5, Interesting)

presidenteloco (659168) | more than 3 years ago | (#34656708)

between single-line multi-server queue and multiple queues.

This occurs in fast food restaurants with the row of cashiers.

This is because some people are "blind" to the fact that there is a single line
situation in effect. These people can be divided into:
1. The generally oblivious. Mindless automatons or cellphone talkers.
2. The socially clueless. Somewhere on the autism spectrum, they don't
understand that queuing is a complex social interaction with rules and etiquette.
3. The obnoxious. Sees the situation but overtly butts in front to stand in front
of one of the cashiers directly, thus forcing others to break rank and sneak in
behind him, since the discipline is shot.
4. The "will be first up against the wall when the revolution comes" devious, who
form their own line like #3 but do it by carefully assessing the situation then actively
pretending that they are in category 1.

So it goes to multiple queues for a while, then some opportunist realizes they
can line up ambiguously in between two cashiers to snag whichever comes open
first, and we're back to single-line til a type 1 to 4 person arrives.

Re:What's so new about single line queue? (2)

icebike (68054) | more than 3 years ago | (#34656462)

I thought we've verify the efficiency of single line queue for many years.

Me too.

I further doubt that most people still think single queue, multiple servers is perceived by customers as the least efficient. People have seen it work well at banks, Airport Security, Post offices, and other places. (Did I just say post offices were efficient?).

The bad rap it gets is usually from the jump-in-front people who perceive the lack of an opportunity to queue-hop as removing one option under their control. Just often enough to enforce this belief, the die-hard queue hopper will get serviced faster than the average customer.

Single queue - multi server "reduces wait time for those that wait".

If you perceive that you are in the slowest line, you probably are, because you wouldn't notice the speed of other lines if you weren't.

one line to many cashiers (0)

Anonymous Coward | more than 3 years ago | (#34656306)

I only see that done at banks, DMV's, and Fry's.

Re:one line to many cashiers (3, Funny)

istartedi (132515) | more than 3 years ago | (#34656336)

The DMV does something right? I think we need another study. :)

Re:one line to many cashiers (-1)

Anonymous Coward | more than 3 years ago | (#34656400)

Offtopic, but regarding your sig, you do understand that its "all intents and purposes," not "intensive purposes" woot! lol...

Re:one line to many cashiers (1)

somersault (912633) | more than 3 years ago | (#34656534)

*whoosh*

Also, you wanted "it's".

Re:one line to many cashiers (-1)

Anonymous Coward | more than 3 years ago | (#34656686)

Also the expression "begs the question" is used incorrectly.... but of course that may have been intentional as well.

Re:one line to many cashiers (0, Insightful)

Anonymous Coward | more than 3 years ago | (#34656740)

As an English major, what I find interesting is that slashdot's grammar nazis are never one of us - the people who have studied language in detail. Rather, they're usually math and computer programmers, for whom formal systems are incredibly important. If you misuse a semicolon in a program, it can fuck shit up. But that's a program or an equation, and while they may use the same glyphs as language, they're not the same thing. Because everyone speaks English, many assume they're experts with it. But, to someone who's studied it extensively, hearing "decimate means 'reduce by 1/10' and any other usage is wrong" is the same as telling a programmer "goto isn't a word" It's taking the rules from one discipline, applying them to another, and then saying the second is in error. Spelling and grammar are important, but they're important for the same reason that dressing nicely is important. People are superficial, and will judge you by superficial things. You can't be sloppy with language and expect people to think you're smart, any more than you can dress like a slob and have people think you're professional. However, as we all know, there's times when you don't need to look professional - and that's what
grammar nazis don't understand. If I say you're an idiot for not wearing a suit to Wal-mart, you'd say I was a shallow dick. If you correct my usage of "begs the question" in anything but a formal philosophical essay, you're being just as bad. For the people who claim they're protecting the language from "degradation," take it from the English majors - language will be fine without you. There's never going to be a point where language degrades so much that we say "fuck it" and die off. Right now, there's hundreds of
different languages being spoken around the world, you think one more is going to destroy communication forever? So the idiom "I could care less" doesn't make sense when parsed
like a computer. Neither does saying "let the cat out of the bag" when you really mean "bring an issue to light." So it makes it slightly harder for a foreign student to learn
the rules, it's not like English is the only language in the world with confusing expressions. The general tone of slashdot often suggests that, because English majors don't have
a lot of job opportunities, we're dumber than scientists or engineers. We may be stupid for choosing the major, but once we've gotten our degree, we know just as much about our
field as a compsci major knows about his. I don't go around assuming that my knowledge of Qbasic lets me tell the admins how easy it is to keep the site up.
-Uncoolio

Re:one line to many cashiers (0)

Anonymous Coward | more than 3 years ago | (#34656514)

Wisconsin DMV has been doing it right for a while. Usually takes 20 minutes or less for me. How do they do it? You talk to someone to get your paperwork which they explain, and they give you a ticket with a number. Since the paperwork is explained before being filled out, there is much less correction needed at the counter. Even if YOU get it right, chances are that a number of people would have made mistakes and been ahead of you in line. Since it's a ticket system... you get to sit and read, people watch, play angry birds, whatever rather than avoiding staring at the back of the head of the person in front of you.

Then again, a significant portion of the improvement is likely to be related to functions being accessible online or at the emissions station.

Re:one line to many cashiers (3, Insightful)

clarkkent09 (1104833) | more than 3 years ago | (#34656422)

The mystery remains though why Fry's has upwards of 60 checkout registers when only 5 or 6 are open at any one time.

Re:one line to many cashiers (5, Funny)

Anonymous Coward | more than 3 years ago | (#34656468)

Its because Frys wants to get a bulk discount from the register repair guy. They wait until 50 of the registers are broken, then call them.

Re:one line to many cashiers (1)

MrEricSir (398214) | more than 3 years ago | (#34656484)

...or why they have door Nazis when you can just walk passed them without showing your receipt.

Re:one line to many cashiers (1)

Bourdain (683477) | more than 3 years ago | (#34656570)

I'd imagine they're given a certain degree of discretion in their job... e.g.

(1) if you offer to show them your bag contents, they probably won't examine it
(2) if you have a small bag it receives less scrutiny
(3) if you otherwise look to be a mature professional, you'll receive less scrutiny

Re:one line to many cashiers (1)

MrEricSir (398214) | more than 3 years ago | (#34656800)

But you're missing the point; if I were stealing, why would I volunteer to show them my bag and/or receipt?

Re:one line to many cashiers (1)

Ethanol-fueled (1125189) | more than 3 years ago | (#34656470)

California DMV uses many lines(er, ticket calls) to many clerks depending on the reason they're there and if they made reservations beforehand.

That being said, I prefer the psychological comfort of many lines. When driving, I would rather to take more total time on a longer detour than wait in standstill traffic because the illusion of motion is less hectic.

Nothing makes me angrier than being herded through that serpentine queue at Best Buy, lined with impulse items, as if I'm so fat or desparate that I can't resist grabbing anything chocolatey or shiney that's put in front of my face. MOOOOOOO!

Re:one line to many cashiers (1)

somersault (912633) | more than 3 years ago | (#34656624)

That being said, I prefer the psychological comfort of many lines. When driving, I would rather to take more total time on a longer detour than wait in standstill traffic because the illusion of motion is less hectic.

That doesn't seem like a good analogy. The single queue is the longer one, and also the one that will keep moving.

I have caused myself occasional psychological distress from gambling on short queues over just taking the longer queue at the self chekouts. It's annoying seeing people join the longer queue after you've joined the shorter one, then also seeing them leave before you have even started checking out.

The impulse items are silly yes, but the system itself is good. Assigning tasks to free processors is much better than predeciding a big list of tasks to go to each processor without knowing how long each will actually take.

Single queue (1)

Fjandr (66656) | more than 3 years ago | (#34656320)

Lots of locations in the US have discovered this. Fry's, REI, and just about any bank or credit union, to name a few.

Re:Single queue (0)

Anonymous Coward | more than 3 years ago | (#34656382)

Wal-Mart in Canada uses the same system if you have less than 10 or so items (quick checkout), depending on the size of the queue extra cashiers get added (or removed).

Re:Single queue (1)

EdIII (1114411) | more than 3 years ago | (#34656658)

To add, I don't think it is perceived as slower psychologically either.

With Fry's they actually have a person directing the next customer in line to the next available cashier. First time I encountered it, I perceived it as faster, due to an increased appearance of organization.

Fry's (1)

RyuuzakiTetsuya (195424) | more than 3 years ago | (#34656328)

I noticed they did this at fry's. Probably for this reason alone.

Re:Fry's (0)

Anonymous Coward | more than 3 years ago | (#34656396)

Yes, but then you have the one employee who simply stands there to point to which register is now available for the next person, despite them having their lights flash when they are open... Couldn't said person simply be another cashier?

Re:Fry's (1)

bhcompy (1877290) | more than 3 years ago | (#34656424)

When there are 60 cash registers it gets kind of hard to see who's open and who's not... and if someone is already going to that register. That's why the guy at Fry's generally stands on a stool or in a high chair.

Re:Fry's (0)

Anonymous Coward | more than 3 years ago | (#34656662)

They have the little lights at Fry's

Re:Fry's (1)

somersault (912633) | more than 3 years ago | (#34656646)

Those guys are there to help out when things go wrong with the self checkouts. Probably also to make sure people aren't just putting things into their pockets instead of scanning them.

Re:Fry's (3, Interesting)

pspahn (1175617) | more than 3 years ago | (#34656460)

I'm sure the fact that they can have a more impressive impulse purchase rack also factors in. They can have a greater variety of items by not having the same small selection of stuff at each register.

Microcenter also does this (at least here in Denver), though it's a much smaller store than any Fry's I've ever been to (even the old ones).

Re:Fry's (1)

somersault (912633) | more than 3 years ago | (#34656664)

I remember an article (probably here) ages ago about Tesco club cards etc. Tesco stopped doing the impulse crap after their research showed it wasn't actually any use. It does give a slightly classier feel if there aren't stupid sweets at the checkouts.

Paging Monty Hall (5, Funny)

schmidt349 (690948) | more than 3 years ago | (#34656330)

See, you have three checkout lines to choose from. You can't see the register from where you are, but at two of the three lines the cashier is a goat...

Science? (0)

camcorder (759720) | more than 3 years ago | (#34656332)

What this has to do with science?

Re:Science? (1)

bigsexyjoe (581721) | more than 3 years ago | (#34656438)

It would seem they mean MATHEMATICALLY, You Are Likely In the Slowest Line. Compared to the misleading titles and summaries we often see on this site, that's a pretty minor error so I'm not going to sweat it.

Re:Science? (1)

Mindcontrolled (1388007) | more than 3 years ago | (#34656618)

As my former sysop used to say when i begged for more processing time on the local linux cluster - "there is no just queuing system, live with it, son."

Re:Science? (1)

Galestar (1473827) | more than 3 years ago | (#34656706)

Actually it would seem they mean "MATHEMATICALLY, You Are Likely NOT In the FASTEST Line."

THAT is quite a major error.

Ironic? (5, Insightful)

timeOday (582209) | more than 3 years ago | (#34656340)

Ironically, the most efficient set-up is to have one line feed into several cashiers... However, this is also perceived by customers as the least efficient, psychologically.

That's a shame, since it's obviously the most fair, and eliminates the annoyance of jockeying into different lines to maybe get a faster one. I guess people like the chance of getting lucky occasionally, even at the cost of utility (average wait time) and fairness? Hmmm, our economy makes so much more sense now.

Unless you are at Fry's Electronics (0)

Anonymous Coward | more than 3 years ago | (#34656342)

At Fry's, you know the line is moving fast because you hardly ever stand still, especially on Black Friday.

One thing Fry's does that most other single-queue places don't do is they "hide the lines" - you can't see the cash registers until you are almost to the head of the line.

Disclaimer: I am a former Fry's employee who shopped there long before working there and still shop there today. Other than that I have no vested interest in Fry's Electronics.

Re:Unless you are at Fry's Electronics (2)

bugs2squash (1132591) | more than 3 years ago | (#34656452)

They also hide the back-scatter xray machines that assure them that you're not stealing anything. I think they only have two sets of doors at the exit way to make sure you breath out any store air you may be concealing in your lungs and have not paid for before you leave.
I don't swear off buying from places because it only hurts me, but I sure do avoid shopping at Frys because of their apparent "every customer is a criminal" mindset.

Re:Unless you are at Fry's Electronics (1)

Dynedain (141758) | more than 3 years ago | (#34656494)

Have you sworn off shopping at Home Depot and Best Buy as well? Because they do the exact same thing.

Re:Unless you are at Fry's Electronics (1)

WrongSizeGlass (838941) | more than 3 years ago | (#34656694)

Our local WalMart checks every receipt before you get to leave the store. They occasionally check your bags & cart to make sure it matches your receipt. They have one really old guy doing it and it backs up a line to exit the store even when there are only a few customers shopping.

Re:Unless you are at Fry's Electronics (1)

mysidia (191772) | more than 3 years ago | (#34656710)

Have you sworn off shopping at Home Depot and Best Buy as well? Because they do the exact same thing.

Which is what exactly?

I shopped at those places, and never encountered any employee showing evidence of an "every customer is a criminal" mindset.

Re:Unless you are at Fry's Electronics (0)

Anonymous Coward | more than 3 years ago | (#34656816)

And I walk right past the receipt checkers every time. If they ask, I say "No thanks", never breaking stride. At least in California they know they can't stop you without either accusing you of shoplifting or being open to false imprisonment charges -- assuming you could find a compliant cop and DA, which is a big IF for most of us, but apparently it's happened (as a guess, to some wantabe Larry Ellison type -- there's enough of them that shop at Fry's -- with both the wallet and dickatude to pursue it).

Same thing at Best Buy (which I really do avoid) or most any place else that pulls this shit. (Yes, I've read the stories about Best Buy threatening to arrest people, and clueless cops willing to do so.) Costco and the like are an exception, since it's in your membership agreement to let them check.

Obvious (5, Insightful)

Arancaytar (966377) | more than 3 years ago | (#34656346)

This is because if any one line slows because of an issue, the entry queue continues to have customers reach check-out optimally

How is that ironic? Doesn't everyone know that? There is no customer configuration in which a single queue isn't more efficient than multiple queues, in average or worst-case waiting time or throughput. You could probably model that and prove it mathematically without needing simulation or experiments.

Re:Obvious (1, Flamebait)

Galestar (1473827) | more than 3 years ago | (#34656430)

Doesn't everyone know that?

You are assuming the average person actually has something on their mind other than what's for dinner and who's on American Idol tonight.

Re:Obvious (0)

Anonymous Coward | more than 3 years ago | (#34656478)

Right. In fact, I've noticed customers spontaneously organizing a single line in fast food restaurants and drug stores that have multiple cashiers behind a counter with no signage or markers for either a single or separate checkout lines. Quite often, someone will cut in and go straight to an open cashier. Usually, people in line just shrug and keep waiting.

Re:Obvious (1)

blackraven14250 (902843) | more than 3 years ago | (#34656542)

The case where single queue is going to be worse is at a place like Wal-mart, where there's going to be quite a few people hopping in ahead of you without repercussion (and the line is usually going to be hundreds long at any given time). They don't use single queue because they don't want to hire security to keep people out of the front of the line.

Seems pretty common sense (1)

Sitnalta (1051230) | more than 3 years ago | (#34656350)

I always thought the one line/multiple cashiers was the most efficient, that way you don't have a single point of failure.

Before this became popular, every time I went to the Best Buy checkout was the exact time somebody wanted to argue over the fucking extended warranty on their $50 DVD player.

Rather like (1)

Dyinobal (1427207) | more than 3 years ago | (#34656374)

I rather like the self service lines. Maybe it's just me but the baggers always put my squish ables in with my canned goods it seems like.

Woot! Microcenter in my area has this (1)

turtleshadow (180842) | more than 3 years ago | (#34656380)

Woot! Microcenter in my area has this ... though these days it still has long lines due to inefficiency of the security locker for small & high value products being purchased by newbies.

Still the last good place in my area to sell good and sometime hard to find odd toys & parts locally. The impulse buy at the the single queue is harder to resist though.

Santa Baby, a Fryes in my state Please!

regardless of the optimal queuing strategy... (1)

Anonymous Coward | more than 3 years ago | (#34656394)

... the whole thing could move about twice as fast if people wouldn't:

* Pay with a check

* ... and not even start making it out until the cashier has already rung up the entire bill.

* Wait until the entire transaction has been calculated before presenting coupons, making the cashier start again from scratch.

* Stand around after their transaction is finished fiddling with lord knows what, but delaying the start of the next transaction because they're still in front of the machine where the next person has to swipe their credit card.

* Yak with the cashier after their transaction is done. If you want to make smalltalk, please don't do it when there are 20 people queued behind you.

* Quibbling about a $0.10 difference in the price of some item, making the cashier suspend processing their items in order to check on something.

* Suddenly remember three more things they need, again suspending the proceedings until someone runs back to obtain them.

* Using their time in front of the cashier as opportunity to button their kids' coats and put their gloves on, as if they can't do that *elsewhere* before departing the store.

And so on. I'll take suboptimal queuing algorithms plus smarter people over an optimal queuing algorithm and dumber people any day. But that doesn't appear to be a choice :-/.

Re:regardless of the optimal queuing strategy... (0)

Anonymous Coward | more than 3 years ago | (#34656554)

I agree lines would move faster if people were more courteous in general about the system rather than optimizing for themselves. That courtesy also goes for cashiers and store management as well. You attribute the quibbling to the purchaser, but had the store not rung up your quince that was on sale as a pear that was marked up, the quibbling wouldn't have to even occur. It's not so much the amount of money, but keeping stores honest. About 40% of our grocery transactions have had a mistake on the part of the cashier (wrong item, wrong price, etc), and those mistakes amounted to over $250 this year (that we caught). Yes, we keep records, but that was more for personal curiosity in verifying a claim someone made to us...turns out they were right about the incidence and magnitude of mistakes on grocery bills around these parts.

Thought of this in another way, a $0.10 mistake per transaction adds up to a lot of padding over advertised prices. I don't care the amount, if you tell me that item X costs Y and then I find out that you either can't tell item X apart from item W, or your system was never updated to reflect Y instead of Y+0.10, I'm going to let you know. And it's your fault for holding up the line, as you altered the agreement at a time when there are 20 people behind me rather than just stated the correct information up front.

Re:regardless of the optimal queuing strategy... (1)

StopKoolaidPoliticsT (1010439) | more than 3 years ago | (#34656754)

Don't forget paying for things in change, especially starting with the lowest denomination first, working their way up until they have to pull out dollars to pay for the rest.

That'll be $8.37:
they get out their change purse, slowly count out 17 pennies, 12 nickles, 11 dimes, 18 quarters, and 2 $1 bills. Meanwhile, you're ready to just pay for their stuff yourself to get them out of the way.

Likewise, you've got the person paying for half of their stuff in food stamps, then the other half (the things like cigarettes and toys that aren't covered) with cash, so they're actually two transactions rather than one.

Inside banks, but not (1)

okle69 (258936) | more than 3 years ago | (#34656410)

outside at the drive-up ATM? this is maddening! I have 3 ATMs at my local BoA and I try to wait for the next one to become available, but most times I'm forced to pick one at random (of course the slowest) because some asshat behind me lays into his horn until I do

Scientifically, the title is bogus (5, Informative)

Galestar (1473827) | more than 3 years ago | (#34656416)

Watching the video, the conclusion that the video makes is "...You are likely not in the fastest line".
That does not necessarily mean that the reverse (the title) is true -- and yet they somehow jump to that conclusion with the title "...You are likely in the slowest Line."

Can we get some people who actually understand this magical thing called "logic" to start editing Slashdot?

Re:Scientifically, the title is bogus (1)

FreakCERS (517467) | more than 3 years ago | (#34656512)

Indeed. It also obviously only applied if there are more than two lines. for n>2, there are n lines that are not the fastest, so odds are n:1 that you are not in the fastest line.
The real question is: when there are only 2 (open) lines (which is often at my local supermarkets) why are you still always in the slowest line? And if you change, why does the new one always grind to a complete stop?

Re:Scientifically, the title is bogus (0)

Anonymous Coward | more than 3 years ago | (#34656776)

The current headline is more dramatic. More page hits.

Yeah (1)

bugs2squash (1132591) | more than 3 years ago | (#34656420)

I tried positioning myself between two queues at the checkouts of my local supermarket to try to merge the lines, someone behind me asked which line I was in and when I replied "both" they sure did give me the stink eye. People just don't want to act in their own best interests.

Incorrect headline (3, Insightful)

matthewncohen (1166231) | more than 3 years ago | (#34656436)

The video actually says that, mathematically, you are likely (2 out of 3 times) not to be in the fastest line.

In his example of three lines, there is still a 2/3 chance that you are not in the slowest line. So unless "one in three" has become "likely," the headline demonstrates a failure at basic maths.

Large retailers should look into this. (1)

LoRdTAW (99712) | more than 3 years ago | (#34656456)

Finally! I love the idea and I thought this should be done for all lanes since I first stood in line for a self checkout machine. Sure the queue looks long but the checkout speed is optimized. Supermarkets, certain retailers and home improvement centers frequently feature self checkout lanes that are fed by a single line. Even if a person has a hard time using the machine, you are pretty much guaranteed the others are speedily checking out and will be done in minutes.

I have always thought it stupid that many retail chains have a dozen or more checkout lanes with a large front aisle clogged with carts and people. There should be one large queue from one end of the building to the other and the checkout lanes should be arranged in a circular or star like shape so the center is where the queue terminates. The queue can be fed from the main aisle and feature benches on one side and racks of last minute crap like magazines, candy and the like. This eliminates the god awful clogged front aisle. It also guarantees you wont get stuck on line behind someone with 100 items and a slow cashier.

Re:Large retailers should look into this. (1)

Ron Bennett (14590) | more than 3 years ago | (#34656780)

Supermarkets, certain retailers and home improvement centers frequently feature self checkout lanes that are fed by a single line. Even if a person has a hard time using the machine, you are pretty much guaranteed the others are speedily checking out and will be done in minutes.

Ditto. The "pretty much guaranteed" checkout time is the sole reason I use self-checkout whenever possible.

Ron

"Ironically?" (1)

BlueScreenO'Life (1813666) | more than 3 years ago | (#34656472)

Ironically, the most efficient set-up is to have one line feed into several cashiers

How is that ironic? It strikes me as mind-numbingly obvious.

Re:"Ironically?" (1)

drew30319 (828970) | more than 3 years ago | (#34656606)

My guess is that it's mostly about initial perception of number of people vs the rate at which the lines are moving. (A) has five lanes with five customers in each queue; (B) has twenty-five customers in one queue.

When you arrive at (A) it looks moderately busy and by comparison at (B) you see a l-o-o-ong line. Obviously the collective queue (B) is processing around 5x the speed of each individual queue (A) but I guess this isn't as obvious (especially initially) as the number of people in each individual queue.

I actually thought that most people knew that single queues were better; I guess not!

You're likely not in the fastest... (5, Insightful)

Idarubicin (579475) | more than 3 years ago | (#34656506)

You're likely not in the fastest line (when compared to your neighbors), but -- unlike the poorly worded story headline -- you're equally likely not in the slowest line. Consider a situation involving three queues: the one you're standing in, and the two (one on each side of you) that you can readily observe. Assign a random speed to each queue/cashier. Do this multiple times. Look at the results. On average, and entirely unsurprisingly, one time in three you'll be in the fastest line; one time in three, you'll be in the slowest line. (And in the remaining third of cases, you'll fall in the middle.)

What's this mean? Two thirds of the time at least one neighboring line will be moving faster than you, and you'll curse and stew and froth about your terrible misfortune. But look on the bright side -- two times out of three, at least one of the neighboring queues will have exactly the same burning jealousy towards your swifter, more efficient checkout.

Ironically, the most efficient set-up is to have one line feed into several cashiers.

Alanis Morissette called; she wants her misused word back. Anyway...the above statement ain't necessarily so. What putting everyone into a single queue does is ensure that the distribution of waiting times is very narrow -- everyone will spend very nearly the same amount of time in the queue before reaching a cashier. However, this setup will almost always impair overall checkout efficiency (measured in customers per hour) by some amount; the average waiting time will be slightly longer. Each time a customer clears the cash desk and the cashier has to wait for the next customer to arrive, time is lost. Since the customer can't unpack his basket while the cashier is finishing with the previous customer, time is lost. It gets worse if a customer at the head of the queue doesn't realize that a cashier is available; everyone stands around waiting that extra bit of time. Yes, this can be offset by having a staff member playing shepherd, but that's extra expense for the store (and wouldn't it be better to have that employee actually manning a cash register?). As well, the store needs to be able to maintain a larger open space by the cash registers through which people can move, to get from the head of the queue to the checkout.

In other words, the one-queue system is less efficient in terms of staff costs, less efficient in terms of average customer waiting time, and less efficient in terms of use of floor space. The only advantage is the one alluded to -- it eliminates the slow cashier/slow customer/bad luck penalty, and ensures that everyone has roughly the same wait. (And for that, I actually do prefer this system -- but I don't pretend that it's really more effiicient. I accept that I'm paying a small premium in average waiting time - and writing off a chance to ever be in a lucky fast line - to avoid the risk of occasional long waits.)

It gets a little more complicated (1)

gstrickler (920733) | more than 3 years ago | (#34656510)

He's correct that in theory a single queue is most efficient overall, however, that doesn't scale well beyond about 8 registers. Fry's Electronics is a great example. The time it takes to walk from the queue to the specific register that is open is wasted time. So, when there are many registers, multiple queues that feed each bank of registers are more efficient. To make that optimal, or nearly optimal, you can start with one line, and split it as many times as needed to have people ready and waiting near each of multiple clusters of registers. There should be at least 4 registers per cluster to minimize the impact of a delay, and no more registers than can be accessed quickly from each queue outlet, which is typically no more than 8 registers. This is similar to the system used at ski lifts. There are multiple lines, including a "singles" line that gets as many people as practical on each chair.

BTW, Best Buy uses a single line setup, at least during busy shopping periods, so it's not just Fry's, banks, and DMV.

Re:It gets a little more complicated (2)

gstrickler (920733) | more than 3 years ago | (#34656700)

An even better example of efficiency is a roller coaster. Typically one or two queues all the way to the loading platform, where people are then directed to very short queues for each row of seats. Substitute checkout lanes for the row of seats, and you have a very efficient system.

I don't have this problem of queues .... (1)

Alain Williams (2972) | more than 3 years ago | (#34656524)

I wonder if it has anything to do with the large blood stained machette that I carry when I go shopping ... :-)

Unlikely to be in the slowest line (1)

Joe Weinman (1964556) | more than 3 years ago | (#34656528)

A line chosen at random from n lines has a 1/n chance of being the slowest. Consequently, except when there is only one line, you are not "likely" to be in the slowest line. When there is only one line, the slowest line is also the fastest one. When there are 2 lines, you have even odds of having selected the slowest line. When there are several, you are just as unlikely to have selected the slowest one as you are to have selected the fastest one.

article title was wrong, video was right (0)

Anonymous Coward | more than 3 years ago | (#34656670)

Certainly it's unlikely that you are in the slowest, but as the video the article embeds points out, it's certainly likely that some line is faster than the one you chose to find yourself (when N>2).

However, they don't get into the other issue which is if you should switch or not (probably not if all lines are approximatly the same length statistically speaking)..

WTF is this noise? (2, Insightful)

KillerCow (213458) | more than 3 years ago | (#34656552)

FIRST... no he dose not prove that you are in the SLOWEST line. He demonstrates that it's most likely that you are NOT IN THE FASTEST LINE. The exact same argument can be used to show that you are likely NOT IN THE SLOWEST line [of course, Slashdot editors and readers have never written any kind of mathematical proof, so the concept of "similarly" is foreign to them].

SECOND... this is elementary probability... barely even high-school level.

Given 3 lines
WLOG, randomly choose one
there is 1/3 probability that your line is the fastest
therefore there is 2/3 probability that your line is not fastest
therefore it is more likely that you are not in the fastest line

THIRD... there is nothing ironic about the single queue being fastest. This is obvious to anyone who has even set next to someone who's brother's dog licked someone who accidentally clicked on the wiki page for queuing theory.

I cannot believe that this drivel got posted. Apparently, Slashdot is now for remedial math. AND the poster (and editors) didn't even get it right! Slashdot editors fail remedial math.

I know this site went to shit about 7 or 8 years ago, but all nerd cred is forever lost in my eyes. It is now just for 12 year old mouth breathers who have no idea what they are talking about.

Logging into my account that I created when I officially gave up on this website. I am not going back to routing *.slashdot.org to 0.0.0.0 so that I am never tempted to return here on a lark.

This also applies to vehicles going on an on-ramp (1)

nhat11 (1608159) | more than 3 years ago | (#34656574)

but noooo those douches try to cut everyone off and try to cut in line, thus slowing the entire process.

It's actually worse than the video shows (4, Insightful)

Solandri (704621) | more than 3 years ago | (#34656578)

If you have 3 lines, you'd think that 2/3rds of the time there's another line which moves faster. But if you're in a slower line, you're spending more time in that line. So with three lines, you're only in the fastest line for 1/3rd of your purchases. But you're in the fastest line less than 1/3rd of the time. The way Fry's does it with a single queue is pretty much the best way (I can think of an exception for those 10 items or fewer lines).

William Feller taught this almost 50 years ago. (1)

MarcAuslander (517215) | more than 3 years ago | (#34656688)

In An Introduction to Probability Theory and Its Applications by William Feller, published before 1968, Feller describes this effect, pointing out that we mentally average over time, not occurrences, and spend most of our time in the slow line.

Heuristical Customer Scheduler, anyone? (1)

zlel (736107) | more than 3 years ago | (#34656616)

We always knew that throughput and response time do not agree. but what about having a display at the EFTPOS displaying customer clearance rate for every single line? In that way customers can perceive themselves as making an informed decision as to which queue they want to be cleared in, while more efficient queues can in fact get more of the workload. And since the customer made the active choice which queue he/she wants to be in, they will feel more personally responsible for whatever speed the queue is moving at.

Totally agreed (0)

Anonymous Coward | more than 3 years ago | (#34656626)

I used to get yelled at almost weekly at Trader joes, where they have space for a single line to feed 2 stations. I did the math and realized, yeah, waiting for either station is faster for everyone involved than picking one at hoping it's the fast one. Every week someone would ask, "Which line are you waiting for?" "Both of them, whichever opens first." They hated that. "You can't take up two stations!?!?" "I'm not, I'm taking up the first free one, otherwise we're just gambling on which one is faster, and given that I've been standing here longer I probably know which one, though the inept lady with her credit card at the bottom of a cavernous purse could be a game changer." Ugh, my fellow Americans.

Nothing ironic about it (0)

topham (32406) | more than 3 years ago | (#34656714)

Nothing ironic about it; but it's so amazingly impersonal.

Walmart has lines like that at a location near me; it's always filled with trailer trash rednecks.

Efficiency bonuses of single line queue (1)

Mr EdgEy (983285) | more than 3 years ago | (#34656732)

I believe there's also a throughput bonus from societal pressures - you're less likely to take time bagging, fiddling with your wallet, etcetera when you notice ten people standing behind you. This is being adopted more and more in the UK through self-service stations in supermarkets.

Why is the single line perceived least efficient? (1)

mark-t (151149) | more than 3 years ago | (#34656812)

Honest question... I'd really like to know. I've *always* seen the single line feeding into multiple cashiers as going far faster, on average.

Where have they been? They don't get out much. (1)

dpbsmith (263124) | more than 3 years ago | (#34656814)

MOST of the stores I go to have single-line queueing, supermarkets being a conspicuous exception. Usually it's done by setting up rope barriers on stands, with a "line starts here" sign.

TSA security and airline check-in work with a single queue. Walt Disney World has been operating that way literally for decades.

And MOST of the places that don't, almost do: clerks at McDonald's, CVS, etc. are trained to say "I can help whoever's next" as soon as they are free, which has much the same effect.

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