That's a old manual Amazon facility. The newer ones use Kiva robots to bring the shelving units to the pickers, rather than the pickers going to the shelving units.<p>The manual system isn't that different from the Sears "schedule system" introduced in 1908.[1] Note the line "pickers don't necessarily pick items for a single or even complete order." That's crucial. Orders are split apart and combined pick lists generated. Picked items then flow towards order assembly stations, which Amazon calls "sort". At any one time, some maximum number of orders are in progress, limited by the number of output boxes at order assembly. Amazon does this with computers; Sears did it with clerks and pick slips, with Sears giving each order an assembly bin for a fixed number of minutes.<p>Separating picking from order assembly and inserting a sort phase reduces the order of the problem. Picking N orders from M items individually means O(N × M) cost, because as inventory becomes larger, the pickers travel more distance. With separate picking and assembly, performance is something like O(log(M) × N) cost, because each picker works in a limited area. That was Sears' big breakthrough.<p>[1] <a href="https://news.google.com/newspapers?nid=1734&dat=19721006&id=bXkcAAAAIBAJ&sjid=AVIEAAAAIBAJ&pg=3170,3159101&hl=en" rel="nofollow">https://news.google.com/newspapers?nid=1734&dat=19721006&id=...</a>
Despite popular belief, most Amazon facilities do NOT use kiva robots. The fulfillment center would have to be completely rebuilt on the inside to accommodate them. Heck, even some new facilities still don't use them. I work over at Amazon in one of their largest fulfillment centers in the USA. To answer your question regarding where a tote is sent in the facility is simple. During each shift, there are any number of queues open (usually about 5). When receiving an item from DA, we will scan an item into a tote and the computer determines, based on the size of the items, where in the facility it needs to go (library, or library deep). Aside from a few exceptions, most items are randomly stowed. The stowers all have a rate, and because of that, will find whatever space fits their needs. Pallet mass (items with a lot of the same quantity to fill a pallet) is checked regularly and pulled from the regular shelves and sent to a sorting area (at least that's what they started doing at my FC) where it can be stowed somewhere in "pallet land." Try not to think too much into where items are stowed, it is pretty much a clusterf*ck across the FC.
The thing I took away from this was mistake minimization. As shipping the wrong item likely results in a mess of expensive actions down the road, it is much much better to make sure that the right item is shipped the first time. To this end they are willing to shuffle their entire warehouse just to prevent similar items from being set next to each other.
This is a pretty great description (disclosure: I currently work at Amazon writing software used inside the Fulfilment Centers). I think an important point is there is big variance between facilities throughout the network. For instance, the use of Kiva robots as mentioned by others here. Meaning if you were to go on tours of other facilities you would definitely see new things at each (and of course many similarities).
As I read through the notes, the one thing I really liked was the 4 day work week. Three days off just makes sense? I belonged to a union, and we had the opportunity to work 4 10hr. days, and the members voted it down. I still don't know why they voted it down.
All, thanks so much for the comments. We wrote this up so long ago; it's really interesting to get feedback now.<p>FWIW, The Infrastructure Observatory is working on more tours like this one, mostly in the NYC area. If you want to get involved (or have an idea for a tour that we should organize), get in touch at <a href="http://infraobservatory.com" rel="nofollow">http://infraobservatory.com</a> or @NYInfraObserve on Twitter.<p>-Spencer
Vaguely interesting, as I suppose a similar tour of, say, a Wal-mart or FedEx logistics center might be.<p>Bonus quote: "Our tour guide used an iPhone, but claimed he’d use a Fire if he wasn’t locked into his carrier."
Does anyone know any good resources/ books on the logistics of setting up and running a fulfillment/distribution facility with the latest tech?
Pretty cool stuff<p>I wished they would add a diagram, even if it's just hand-drawn. It's would have been much easier to visualize, especially the detailed parts.<p>Also the naming is sometimes inconsistent across the different authors. e.g. Sometimes folks are called "associates", sometimes "sorters". It got confusing quickly. Would be nice if the naming was clearer
He doesn't specify exactly how cubbies are selected at the "inbound" stage, beyond saying it's random. I assume it's left up to the associate's own whims and judgements? I imagine the "no identical items in adjacent cubbies" rule improves the potential for picking the same item in parallel while preventing too much concentration, improving availability from different locations. I wonder what other constraints they are given for this stage.
PDF @ <a href="https://docs.google.com/document/export?0=mp&1=ws&2=print&3=1&format=pdf&id=1F12fyVF0PO2fSmkOI2_R1IFigTaznaertxiVXlEbas4" rel="nofollow">https://docs.google.com/document/export?0=mp&1=ws&2=print&3=...</a>
I have no skin in this game and really don't know much about what is going on, but really appreciated that rundown. I've always wanted to know what goes on inside these places.
And something unrelated I've learnt about Google Docs:<p>"Wow, this file is really popular! Some tools might be unavailable until the crowd clears."