Scan process
This article outlines the steps to scanning inventory in and out of inventory, as well as resetting inventory to identify what is on hand.
Adding Inventory
Any time items are added to your inventory, a ledger of the origin of the item, and where it came from (such as the Order #) should exist.
Retail Stores - Most retail stores can audit daily. Absent items can be compared against sold items to confirm.
Receiving Transfers
Receiving Purchases
Shipping Sales Orders
Shipping Transfers
Review Absent List
Start with Audit
Compare Inventory