A single line to 3 cashiers is ~3x faster than a separate line for each cashier • Hacker News Board

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#91

Post by JadeNB » Thu, Dec 08, 2011, 7:05 PM UTC

Muzza wrote: post #31

smackfu wrote: post #18

Earlier quoted context omitted.

Around here, the grocery self-checkout works the same as the normal checkouts, mainly because they just replaced the normal ones in place. (Also, self-checkouts suck. I bet their throughput is terrible compared to manned checkout lines. That teenage checkout girl is WAY better than I am at scanning stuff.)

Self-checkouts don't have to suck, though. The version where you scan all your items at a single location is clearly crap, but there are systems where you get a small hand-held device when entering the store so you can scan your items as you go along.

> Self-checkouts don't have to suck, though. The version where you scan all your items at a single location is clearly crap, but there are systems where you get a small hand-held device when entering the store so you can scan your items as you go along.

This is presumably much better for throughput, but much worse for making sure that what you're leaving with is what you purchased. (Also, how does it accommodate a decision to put something back? I've never seen such a system.)

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#92

Post by mc32 » Thu, Dec 08, 2011, 7:09 PM UTC

AndyNemmity wrote: post #86

cheald wrote: post #74

Earlier quoted context omitted.

Fry's Electronics does the single line thing, and any time there is a line, I feel like I end up standing in it longer than I would at a grocery story. I suspect this is probably psychological, but letting me, as the shopper, pick the line I want to stand in puts me in charge of how long I wait. If I pick a bad line, it's my fault for picking the bad line. When there's just one line available, I don't get that choice…

I go to Fry's a ton, and it always seems to go much quicker, but I agree, psychologically standing in a tremendously huge line feels worse.

--which is why Delis‡ traditionally give you a numbered tag. It's a single line, but you can go about and not feel "constricted" to the queue (tail).

Don't forget, Frys also has a "semaphore" who cues people to the next register.

‡among many places like hospitals, information centers (DMVs), etc.

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#93

Post by prodigal_erik » Thu, Dec 08, 2011, 7:09 PM UTC

cheald wrote: post #74

rdtsc wrote: post #43

Earlier quoted context omitted.

Not trying to be condescending but doesn't it surprise anyone here that this is _not_ obvious? At least on this site, there are still people doubting or debating this. So I am wondering why don't stores do this already. And I believe it is because of perceptions. They understand that time will be saved, however, they realize that most people will be scared by a long line. One long line that moves fast will still appe…

Fry's Electronics does the single line thing, and any time there is a line, I feel like I end up standing in it longer than I would at a grocery story. I suspect this is probably psychological, but letting me, as the shopper, pick the line I want to stand in puts me in charge of how long I wait. If I pick a bad line, it's my fault for picking the bad line. When there's just one line available, I don't get that choice…

When I have to choose a line I find myself harshly judging the people around me, because every difference can impose a cost in boredom and lost leisure time. "This guy's old and worn out. They seem kind of foreign, won't understand the cashier. That one looks poor, probably uses a lot of coupons and argues about what's discounted. They're paying all their attention to their kid instead of getting out of everyone's way." It may be the most socially corrosive thing I routinely do.

Edit: and I think I just convinced myself to get a smartphone (I'm reluctant to bring a paperback, it might look like shoplifting because they sell those).

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#94

Post by squidfood » Thu, Dec 08, 2011, 7:09 PM UTC

AndyNemmity wrote: post #86

cheald wrote: post #74

Earlier quoted context omitted.

Fry's Electronics does the single line thing, and any time there is a line, I feel like I end up standing in it longer than I would at a grocery story. I suspect this is probably psychological, but letting me, as the shopper, pick the line I want to stand in puts me in charge of how long I wait. If I pick a bad line, it's my fault for picking the bad line. When there's just one line available, I don't get that choice…

I go to Fry's a ton, and it always seems to go much quicker, but I agree, psychologically standing in a tremendously huge line feels worse.

My experience is exactly opposite.

Sure a big line is initially discouraging. But while in line, if I've chosen one of several lines, I fixate: is my chosen cashier a slow idiot? is a customer ahead of me fumbling for change? Should I jump? There's another line opening, should I get ready to run for it? I invariably end up at the front more directly annoyed and snippy at "my" cashier and the whole process. With a single line, I can see everything humming along, moving forward more often, if one transaction takes a while, so what, it's not a race, I relax more, I'll get there.

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#95

Post by ryusage » Thu, Dec 08, 2011, 7:10 PM UTC

nlawalker wrote: post #9

Most of the grocery stores in my area have installed self-checkout systems that are especially great if you just have a handful of items that all have UPCs (no produce or bagged bulk), don't have any items requiring an age check and possess at least the intelligence of a fifth grader. I mention this not just because it's relevant to the idea of waiting in line at a store, but because in every store where I've seen th…

The most interesting fact about the self-checkout systems, in my mind, is that they actually have no designated area or instructions for how lines should form. People just intuitively wait outside the general self-checkout area, and use the machines as they become available. So, at least in some circumstances, the single queue system obviously can make a lot of sense to people.

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#96

Post by dextorious » Thu, Dec 08, 2011, 7:11 PM UTC

eiji wrote: post #85

smackfu wrote: post #18

Earlier quoted context omitted.

Around here, the grocery self-checkout works the same as the normal checkouts, mainly because they just replaced the normal ones in place. (Also, self-checkouts suck. I bet their throughput is terrible compared to manned checkout lines. That teenage checkout girl is WAY better than I am at scanning stuff.)

Self-checkouts are not just about speed. They also appeal to specific kind of people. I use them because I don't want to interact with someone just to get some groceries. I know, it's kind of sad, but I don't want to say 'Hi' and 'Thank you' and I don't want 5 bags when 2 would suffice and don't want to explain that, so I just do it myself.

You must be very popular at parties.

(Let the downvoting begin)

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#97

Post by nhebb » Thu, Dec 08, 2011, 7:15 PM UTC

cheald wrote: post #74

rdtsc wrote: post #43

Earlier quoted context omitted.

Not trying to be condescending but doesn't it surprise anyone here that this is _not_ obvious? At least on this site, there are still people doubting or debating this. So I am wondering why don't stores do this already. And I believe it is because of perceptions. They understand that time will be saved, however, they realize that most people will be scared by a long line. One long line that moves fast will still appe…

Fry's Electronics does the single line thing, and any time there is a line, I feel like I end up standing in it longer than I would at a grocery story. I suspect this is probably psychological, but letting me, as the shopper, pick the line I want to stand in puts me in charge of how long I wait. If I pick a bad line, it's my fault for picking the bad line. When there's just one line available, I don't get that choice…

Fry's might not be a good example because many of their orders are ticketed items, so the cashier does more than just ring you up. For example, last week I bought a hard drive there, and it took a minute for the cashier to retrieve the item then print out the warranty disclaimer/waiver. Target, on the other hand, has checkout arrangement that looks like a rabbit warren.

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#98

Post by tomkarlo » Thu, Dec 08, 2011, 7:19 PM UTC

finnw wrote: post #83

tomkarlo wrote: post #67

Earlier quoted context omitted.

Having more than one line materially increases stress for shoppers, because the choice implies they might be on the "wrong" line. So they worry more about how fast they're moving, etc. If you only have one line, you can tell people exactly how long the wait is (because the average transaction time is very stable) and customers don't have to worry about making the right choice.

Having one combined line can increase stress for shoppers too, especially if the line isn't clearly marked by barriers. What happens is, another customer comes along, sees three cashiers and one queue (in the middle) and decides to join the "empty queue" in front of the cashier at either end. Of course they know there's only one queue and that they are queue jumping, but they calculate that they can pretend they didn…

This is why you really need a new store design. At Best Buy and Whole Foods here, there's a long line that channels into a checkout area that's only reachable via that line. So there's now worry about cutting, and customers naturally form the line as they follow the route into the checkout area.

It's worth noting that WF does use 2-3 lines in a lot of stores where they don't have a long enough space. But then what they do is have a system that signals which line gets to head a register next (and does so in a set rotation), so it's effectively the same as a single long line.

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#99

Post by tomkarlo » Thu, Dec 08, 2011, 7:22 PM UTC

When I interviewed for a PM job, one of my full hours was spent being asked to design a better checkout system for a grocery store, and show the math around how many registers were needed to ensure a certain maximum wait on line. It was definitely an interesting case study to use.

Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier

#100

Post by anamax » Thu, Dec 08, 2011, 7:25 PM UTC

cheald wrote: post #74

rdtsc wrote: post #43

Earlier quoted context omitted.

Not trying to be condescending but doesn't it surprise anyone here that this is _not_ obvious? At least on this site, there are still people doubting or debating this. So I am wondering why don't stores do this already. And I believe it is because of perceptions. They understand that time will be saved, however, they realize that most people will be scared by a long line. One long line that moves fast will still appe…

Fry's Electronics does the single line thing, and any time there is a line, I feel like I end up standing in it longer than I would at a grocery story. I suspect this is probably psychological, but letting me, as the shopper, pick the line I want to stand in puts me in charge of how long I wait. If I pick a bad line, it's my fault for picking the bad line. When there's just one line available, I don't get that choice…

The single line has another property that fry's exploits.

The single line is longer, so it has more space in which to pitch impulse purchases. (It's probably shorter than the sum of the "equivalent" individual lines.)