Answer
Ask vendors to show the actual integration mechanism rather than just the scanning screen. Modern implementations call program interfaces or APIs directly against Db2 for i order and inventory files, while older or cheaper integrations still rely on screen-scraping a 5250 session, which breaks any time a field moves or a program gets patched. If the vendor cannot explain whether they use exit points, open database APIs, or direct program calls, treat that as a red flag rather than a technical detail to sort out later.
Pilot the integration on one workflow, such as a single dock door for receiving or one product category for picking, before rolling it across the warehouse. That scope lets you verify duplicate-scan prevention, how exceptions like a damaged label or a mis-picked item get flagged back to the ERP, and how reconciliation happens if a device goes offline mid-transaction. Buyers should also confirm what happens to in-flight scans when an RPG program behind the integration gets updated, since an integration that silently fails during a PTF cycle can go unnoticed until inventory counts stop matching reality.