I am not an expert at this but I did do inventory for a food bank for 2 years. We used a program called Ceres (I think, been 10 years) that allowed us to scan pallets into individual slots. So this program was a database that had all of the possible pallet slots in the entire warehouse (including separate refrigerated and frozen areas).
There were barcodes taped to the bottom bin that had the slot number and level (letters A through F (sometimes less if slots were taller)). When an order came in, it would get entered into the system manually. There were codes that were assigned to the pallet and then it would get scanned into a slot. That was second shift (night)
Then after the product was all in place, order picking would happen P(first shift - day). Customer orders would go through Ceres and all the different products ordered would print out on paper which pallets to pick how many of each specific product. from. The orders would get wrapped up, new barcode stickers, and scanned into an outgoing rack. Then the outgoing orders (both shifts) would be printed out with locations for each pallet, they would get loaded from there onto outgoing trucks.
Inventory would go through and scan all the pallets after order picking was done, and enter in the amounts actually there. Ceres would reconcile the differences from virtual amounts and actual amounts, thus leading to losses being found (theft, or damage, or lost product). After that we would run drops which was where Ceres calculated the next days orders and told us how many pallets of each product needed to be dropped into the order picking locations. During particularly busy times, you could run the report for several days worth of orders. Then drop all that wherever possible, or at least group it together to make order picking easier.
At the end of the 4th quarter, we would scan ever single pallet in the warehouse and enter in the quantities. This would uncovering any more losses that were not found before. Ceres would I guess valuate the product in inventory so that assets could be determined for accounting .
Like I said, I don't exactly remember how Ceres worked, but I worked in several different departments and learned the warehouse operations very well