What is purchase order software?
Purchase order software runs buying from the first request to the paid invoice. Requirements become RFQs and quotations, the chosen offer becomes an approved purchase order, goods are received against it on a GRN, and invoices are checked against what actually arrived. Each document links back to the one before it.
In many plants the PO is a printed PDF and everything after it happens in email. Nobody can say which lines are still open, what date the supplier committed to, or whether the invoice on the desk is for parts that were ever received. Shortages surface on the shop floor, not on the buyer's screen.