Ideally, from an IT perspective, you would solve this in your ordering system, so that it just becomes part of your processes. I don't know what systems you use, but basically when your pick/pack your order, you should scan for lot, as well as, part number. That then becomes an attribute in your ERP system that could be queried against. It typically is a second bar code that is scanned. If you think of a computer, someone would scan the part number, but then also scan the serial number for that unit, so it can be traced. Same concept. Depending upon the products, maybe that barcode is on your end-user package, but more likely it's the bin that product is in. There is a lot in your situation that I don't know, so this might not work, but that is how I would look at it.
Another means would be to track it at a higher level. It would mean recalling a lot more product, but you could just track the day you start shipping a lot and a day you stop shipping a lot and recall all of the sales within that time period for that item. Messier, and more expensive if you have a recall, but perhaps something that would work easier for you.
If you can provide more specifics about how you operate, I can try and recommend something more specific. Involve your IT person/staff and use technology to keep track of it if possible. Manual processes suck and you are going to have to prove that your processes work and that you can id the recalled product completely (or you will be recalling everything).
Anyway, good luck....
PS: Don't forget to think about how you handled returned product cause that process may now need to change as well.
Edited by tsebring, 24 October 2019 - 12:23 PM.