mock Hospital Inventory

I need to make a easy but efficient way to keep track of all of our inventory. Most of our inventory is hospital supplies so needles, foley’s, ivs, and other common hospital supplies.

I am using google sheets and want to make an inventory list that automatically updates whenever something is scanned in or out using my google site form. I have QR codes made from QRCode-monkey that are being used to scan stuff in or out. But I am not sure how I can make my inventory automatically update when things are scanned and also make a threshold of when things need to be reordered.