The POS software that I use is made for the tool business, but I will say that Pete's method of barcode label check in works for me. My software prints barcodes with every PO/Invoice, and when I apply them to the product, it is automatically checked.

I do not use the scanning capabilities with the software. I simply enter the part numbers into the computer. I don't see the advantage of barcodes for every day selling. It could be handy for inventory time, however.