Remarkably similar in design to hyper-threading. Lol!
A single line to 3 cashiers is ~3x faster than a separate line for each cashier
51–60 of 172 posts
Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier
#52What I didn't see in this article is why retailers don't do this today. I see a lot of positives listed and no negatives, so it seems like a no-brainer, right? Yet the biggest retailers like Walmart and Target have tons of lanes, and even do staggered front/back lanes which are terrible for the customers. Is it because there are negative feelings to seeing a long line, and that people do not expect it to be fast so t…
In the UK, Tesco and other grocery retailers do this. I've seen this in place in the USA at the Whole Foods at Columbus Circle (an enormously crowded store that moves along well).
Based on these data points, it would seem as though more crowded places use this optimization.
Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier
#53What I didn't see in this article is why retailers don't do this today. I see a lot of positives listed and no negatives, so it seems like a no-brainer, right? Yet the biggest retailers like Walmart and Target have tons of lanes, and even do staggered front/back lanes which are terrible for the customers. Is it because there are negative feelings to seeing a long line, and that people do not expect it to be fast so t…
It's being rolled out slowly. Target in Emeryville has a rather advanced queuing system like this, but customers definitely don't like it and don't necessarily realize it's faster, perhaps because Target has less cashiers as a result of the decreased wait.
Edit: Yelp says this line system has been eliminated. http://www.yelp.com/biz/target-emeryville-2
Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier
#54There's interesting work on queuing theory. In practice, each shopper picks the queue that she thinks is least loaded. How many queue lengths do you need to sample? It turns out that if you sample just two queue lengths, you get a huge benefit (in terms of reducing the avg queue length), but not so much if you sample more.
See "Power of two random choices": http://www.eecs.harvard.edu/~michaelm/postscripts/handbook20...
EDIT: link
Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier
#55What I didn't see in this article is why retailers don't do this today. I see a lot of positives listed and no negatives, so it seems like a no-brainer, right? Yet the biggest retailers like Walmart and Target have tons of lanes, and even do staggered front/back lanes which are terrible for the customers. Is it because there are negative feelings to seeing a long line, and that people do not expect it to be fast so t…
Besides the other reasons, retailers have incentives to keep you in the store as long as possible without you getting so annoyed you won't come back, especially near the checkout where they put their most shiny things out for you to impulse buy.
Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier
#56Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier
#57FYI: This is an example of the branch of mathematics called queueing theory. http://en.wikipedia.org/wiki/Queueing_theory It's a fascinating study requiring a good knowledge of probability to use beyond the simplified models. It turns out from the math that throughput using a single queue is better than using multiple queues.
And if anyone was wondering, it's not exactly new. When did I learn the proof that single queue is faster than multi-queue? In undergrad 20 years ago. And yet so many multi-queue setups out there...
Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier
#58What I didn't see in this article is why retailers don't do this today. I see a lot of positives listed and no negatives, so it seems like a no-brainer, right? Yet the biggest retailers like Walmart and Target have tons of lanes, and even do staggered front/back lanes which are terrible for the customers. Is it because there are negative feelings to seeing a long line, and that people do not expect it to be fast so t…
Some places do this. Fry's Electronics, for example. It works fine. Some supermarkets I've been in do this for their express lines ("10 items or less"). Oh, and airline ticket counters are routinely run this way.
Add to this, Fry's also stacks the "wait line" area with lots of high-margin low-cost goodies like candies and trinkets. I myself have succumbed to grabbing some trail mix or a thumbdrive while waiting there.
Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier
#59It becomes even more obvious if you think of it like scheduling processes on a CPU. Why needlessly set CPU affinity and only run on a single CPU when you could just take the next available timeslice on any CPU?
> Why needlessly set CPU affinity There are practical reasons to do that. That is common in realtime systems. Trying to isolate the cpu for a particular process. So that is available faster when that process needs it. You could also have n-realtime processes. You don't want them competing for the same CPU if you know ahead of time you can allocate a CPU for each one of them. Another reason is caching. For example you…
CPU affinity certainly has a useful purpose; however, I said "needlessly". As in, what if every process on your system selected a CPU when it started, and just waited for that CPU, to the point of leaving other CPUs idle or underutilized? And what happens when you get stuck behind a process which requires a huge pile of CPU resources? The problem becomes even worse with batch processing: every process must run to completion before the next one for that CPU can run.
Re: A single line to 3 cashiers is ~3x faster than a separate line for each cashier
#60There are two Trader Joe's near me. One does a single line and the others have one for each cashier. I never go to the one with multiple lines. I hate it. The big, huge like that goes to the back of the store for the one with a single line.... I love it. I moves fast and I don't need to worry about picking a line. Even if it went just as fast as the other type, I'd prefer it, but now there's reason to love it even more.