One myth about lean is that it perfects processes so well you don't need to check for accuracy. Wrong. It'd be nice if it did, but it doesn't. The checking station doesn't go away. It just stops being a station. Instead you check everywhere, all the time.
Here's an analogy that might help explain what I mean.
Let's say you're out shopping. Something costs $35 and you pay $40. You get change. You count it. You have $4. You correct the clerk and they give you another dollar. You go to the next store, pay for something, count the change, correct it if it needs correcting, and so on.
This seems totally normal because we all do it every day. Now imagine another scenario where you didn't count your change at each stop. Instead you waited till you got home and then counted all the change from all the shops to see if you had the right amount.
That's batching. That's what we do now in production at the check station by batch checking the pickers. It's also — sneak preview, thanks Betty! — something we're looking at eliminating next year.