Comment by kube-system

3 days ago

They are individually slow but highly multithreaded. The single cashier that stores hire these days may have a 10% higher clock speed, but their queue length is high.

Sounds like the problem is that we aren't hiring enough cashiers.

Using a Kroger self-checkout is tantamount to waterboarding. Hesitate for a quarter of a second before placing your item on the scale? Angry prompt. Put an item on the scanner (which itself is another scale) but it doesn't scan within half a second? Angry prompt. Get three angry prompts? Now you get a fourth angry prompt, except this one can only be dismissed by a staff member, and we've already established that they're few and far between.

I've given up on actually bagging my items while checking out. I can't rearrange anything in the bags, or move the bags, without the checkout machine throwing a hissy fit. So no, it's not actually faster, because I have to bag everything after paying for it. It totally breaks the pipeline of the checkout.

  • There are a few problems.

    - Real estate: Self-checkout takes minimal floor space. Stores can fit ~10 stations in the area of 2 cashier lanes. Even if you hire more cashiers, there’s no room to add lanes.

    - Demand vs. staffing: Checkout demand is dynamic, staffing is static. You can’t instantly add cashiers during a rush, and you don’t want them idle when it’s slow. Self-checkout stations are basically ~free to run.

    - Cart size: Trader Joe’s works without self-checkout because their stores are small, carts are tiny, and checkouts max ~20 items. Their cashier lanes are smaller but occupy a bigger share of store space than Walmart or Kroger. In big stores with huge carts, no one wants to be stuck behind a full cart. Once you pick a lane, you’re locked in even if another line moves faster, whereas self checkout lanes are serviced by all machines.

    But in the big stores with huge inventories, no one wants to wait behind a person with a huge cart and once you commit to a lane, you're stuck, even if someone else finishes faster.