No it doesn’t.
Not just because they can be badly calibrated, but also because the range of weight they have to deal with must make it hard to manage any sane range.
The only SCO I’ve seen doing a decent job at dealing with weight use a binary check (“was there any product at all added to the to total weight of the basket ?”) and they still miss products like lollipops or anything too light to pass the range.
Sure much more reliable system could be built, especially at Amazon’s engineering scale. But so far supermarkets are mediocre at best at this game.
Compared the AH in the Netherlands where you just scan the barcode on all your things and they really don't care about the weight or where you put them after scanning.
I'm sure there will be a tiny percentage extra fraud that Tesco may catch with this, but given the choice I don't shop there due to the shitty user experience. That's got to cost them more in lost revenue than the fraud they stop.
I wonder if they built in correlation of items which on a mis-weighed basket.
Those bring their own set of issues, can be difficult to understand and use from the customer, yet they still felt way easier to deal with than the SCO experience.
The handheld scanners are easy to use. All it has is a trigger for scanning (which everyone knows how to do), scroll buttons, and a delete button if you make a mistake.
I checked my order history and my last orders are around:
- 350g
- 600g
- 200g
- 500g
- 5kg
- 120g
a box with empty packing would fit within a pound for most of these. I don't intend to nitpick your back of the enveloppe calculation, just that it's not as simple as it seems.
I don't know if I am the typical amazon shopper, but on my 35 orders in the last 6 months the above pattern is repeating with mainly very small items (like cables, dongles etc.) and one big heavy package from time to time.
It can be done, just not sure the parties involved are willing to commit to that level of accuracy.
Weirdly, Amazon still made me mail back the underweight one (I would happily have paid the correct amount for the smaller quantity to save the trouble of remailing) and a few days later sent out the correct one. You'd think in this case they have a record of the actual weight of the package and could sort things out instantly, but apparently not.
Verifying shape would be difficult without knowing what to expect beforehand, but can also be gamed.
You won’t get the precision of supermarket weighting if you are dealing with diverse restaurants with a dynamic menu.
Seems like when the items arrived at the fulfilment centre, they got mis-scanned and ended up comingled. Presumably that's the stage where you can check weight and volume - eg does this item fit with the known dimensions.
This check must be made somewhere otherwise people wouldn't bother returning high value electronics with rocks inside (presumably someone does a cursory check of weight before the inventory gets comingled again).
For a technology example, you might get a network card with a UPC barcode, but also a MAC address barcode, and a manufacturer's part number barcode. A wholesaler/ manufacturer sells boxes of 20 items to resellers? The outer box will have a barcode. That box got sent by courier? Three barcodes on some mailing labels.
So at a goods-in station, the usual response to "multiple barcodes, some don't make sense" is "Keep trying until you find one that does make sense"
What baffles me is that the store/software can't build a dictionary of "known misdirection" barcodes, like "this is the shipping carton not the product itself, fault and tell the user to rescan, but don't just lock up" when they're seen.
The scanners in supermarkets are made by the same companies and I would assume run on the same software. However, it might be more difficult to ensure a specific type of barcode is used on 100% of products in the store. So if you see the scanner picking up the wrong barcode at the check-out aisle, it is most likely either the scanner is not programmed correctly, or the scanned barcode is the same type as a valid barcode used somewhere else in the building.
As far as handling faults, that would probably be done on the POS system, not the scanner itself. The scanner software is perfectly capable of handling errors in different ways (for example, sending a specific code to indicate two different non-matching barcodes were read in the same pass), but from a functional standpoint, the scanner is 'dumb'.