Our scenario is - Kanban for production which is managed by workshop users via kanban signal PKBC (scanner shooting barcode printed on kanban card); Kanban for purchasing which is controlled by purchasers via transaction PK13N (mouse click on button "EMPTY" or "FULL"); Purchase orders are sent to suppliers directly via output message setup.
Now I get a problem. From time to time the production kanban cards are contaminated and barcodes become not clear enough to shoot by scanner. Then workshop users have to type the barcode in transaction PKBC. But mistake happens - often they type a wrong barcode and probably that "wrong barcode" leads to a purchase kanban. So finally they trigger a purchase kanban to EMPTY and generate a PO in the system and unfortunately that PO will be sent to the supplier automatically.
What I have been doing is that there is a job running twice a day to monitor all the POs created by workshop users and I will inform purchasers for cancellation from both the system and the supplier. However sometimes it's still causing confusion to our suppliers.
My question is whether I can restrict a purchase kanban card from being shot via Kanban signal? Is there a better way of controlling the problem? Any input would be highly appreciated