Functionalbeginner
Materials Management (MM): Procure-to-Pay Cycle
The end-to-end process from purchase requisition through goods receipt to invoice verification in SAP MM.
Procure-to-pay (P2P) is the backbone process of SAP MM and one of the very first things any MM consultant or ABAP developer supporting logistics gets asked to explain, because interviewers use it to check whether a candidate understands the full document flow rather than just isolated transaction codes.
The GR/IR account is like a temporary escrow holding pen - goods arrive and get counted (GR) before the bill (invoice) shows up, so the system parks the expected cost there until the invoice finally arrives and the two are matched and cleared together, like reconciling a delivery receipt against the invoice that follows days later.
Key Concepts
1
The cycle typically starts with a purchase requisition (PR, ME51N) - an internal request to buy something - which can be converted into a purchase order (PO, ME21N) either manually or through automated sourcing rules, source lists, and quota arrangements that determine which vendor should fulfill it. The PO is a legal document sent to the vendor specifying material, quantity, price, and delivery terms, and it carries account assignment (cost center, internal order, or none for stock items) determining what G/L accounts get hit financially.
ME51NME21N
2
When goods physically arrive, a goods receipt (GR, MIGO, movement type 101 for a standard PO GR) updates stock quantity and simultaneously posts an accounting document debiting inventory and crediting a GR/IR (goods receipt/invoice receipt) clearing account - a suspense account that exists precisely because the goods receipt and the vendor invoice usually arrive at different times. Invoice verification (MIRO) then matches the vendor's invoice against the PO and the GR (the three-way match: PO, GR, invoice), clearing the GR/IR account and posting a vendor payable, and any quantity or price discrepancies beyond configured tolerances land in a blocked-invoice status requiring manual release.
MIGOMIRO
3
A well-rounded answer also touches on the valuation impact - standard price versus moving average price materials post GR/IR postings differently - and mentions common troubleshooting scenarios like GR/IR account reconciliation reports (MB5S) used at period-end to investigate open balances where goods receipts and invoices haven't yet matched.
MB5S