The purchase cycle in SAP S/4HANA

At station three you built the structure. Here the first real money moves through it — and it moves through the clearest window the product has onto its own logic.

Understand this cycle with its documents and its entries and you have understood half of materials management, and half of how the system thinks about money.

The five documents, and which of them touch the ledgers

Document	What it asserts	Does it touch the ledgers?	What changes
Purchase requisition	“A department needs something”	No	Nothing financially
Purchase order	“We contracted with a supplier on a quantity and a price”	No	A commitment, not an entry
Goods receipt	“The quantity actually arrived”	Yes	Stock rises, and an intermediate account is debited
Supplier invoice	“The supplier has billed us”	Yes	The intermediate account clears, the payable rises
Payment	“We paid”	Yes	The payable falls, cash falls

Read the third column across rows two and three. The purchase order produces no accounting entry; the receipt does. That is the first sentence an accountant arriving from a manual system has to absorb: a contractual commitment is not an expense, and goods in transit are not in your books until they land.

Goods received not invoiced — half the understanding sits in one account

Between receipt and invoice there is a gap in time: the goods have arrived and the invoice has not. During that window the company genuinely owes money and holds no creditor document to prove it.

The system answers that with an intermediate account, debited at receipt and cleared when the invoice is posted. In practice that means two things:

• Its balance at month end equals goods you received and have not yet been billed for.
• A swollen balance means late supplier invoices, or incomplete receipts, or both.

This is the first account an auditor opens in this system. It is also the cleanest test of your own understanding: anyone who can explain why it is not zero at month end has understood the cycle; anyone who thinks it ought to be zero has not.

Three-way matching — the governing idea

The system does not accept a supplier invoice merely because it arrived. It compares it against three sources:

1. What we contracted for — the purchase order: price, quantity, terms.
2. What we actually received — the goods receipt: the quantity that landed.
3. What the supplier is asking for — the invoice itself.

Any divergence stops the invoice rather than passing it.

That is the most important control in the purchase cycle, and its justification is simple and expensive: companies pay the same invoice twice, pay a higher price than the one agreed, and pay for goods that never arrived. All three are prevented here.

The knowledge that separates a consultant from a data-entry clerk is knowing the difference types:

Difference	What it means	The correct remedy
Price difference	The supplier billed at a price other than the agreed one	A contractual review, not an edit to the invoice
Quantity difference	Billed for more than was received	A receipt review, or a debit note
No receipt at all	Billed before shipping	Hold until the goods arrive
Within a tolerance limit	A small difference accepted in advance	Passes automatically with a difference entry

The last row deserves a pause. A tolerance limit is not laxity; it is a written management decision that trivial differences do not merit an employee’s time. Set it wide and you open a hole; set it to zero and you paralyse the accounts department over pennies.

The idea underneath, which is not this product’s

This cycle is not specific to SAP. Its structure is identical in every ERP on earth — the screen names change, the logic does not. Which matters unusually much at this station on this path specifically, because you may not have an environment yet: what you learn here travels with you wherever you go.

The cycle explained independently of any product, with its control points and their common failures, is in the purchase cycle from requisition to payment.

What you actually do at this station

If you have an environment, run the full cycle and open the entries after every step — not at the end. Reading after each document is what teaches; reading at the end gives you a correct result with no understanding under it.

If you do not, the following is done on paper and appears in your portfolio:

• Write the expected entry for each of the five steps: the debit account, the credit account, the amount.
• Design three difference cases — price, quantity, and an invoice with no receipt — and write the remedy for each.
• Propose a tolerance limit for a company you know, as an amount and a percentage, with one line of justification.
• Explain the intermediate account’s balance at a hypothetical month end: where it came from, and when it should worry you.

The three commonest errors

One: posting the invoice with no receipt, to speed up payment. It looks like a fix for a timing squeeze and it is an abolition of three-way matching from the inside. The result is a control that remains active in the documentation and inactive in reality.

Two: correcting a price difference by amending the purchase order retrospectively. The order is a contractual document, and editing it to agree with what the supplier billed makes the match certify itself. A difference is settled contractually, not by erasing its trace.

Three: ignoring the unit of measure. Buying by the carton, receiving by the piece and invoicing by the kilo produces differences that read as price errors and are conversion errors — which is why the material master’s views were flagged at station three: it is settled there, not here.

What these details do to a real project’s cost — and to the number of consultant-days you end up buying — is set out in the SAP S/4HANA guide.

The acceptance test for this station

1. Write the five documents in order from memory, marking which of them produce an entry.
2. Explain the intermediate account in three lines, and why it is not normally zero.
3. Design three difference cases with a written remedy for each.
4. Propose a tolerance limit with a figure, a percentage and a reason.
5. Explain to a non-accountant why the purchase order produces no entry. Anyone who can explain it without jargon has understood it.

What comes next

Money went out. The next station reverses the direction: the sales cycle — from customer order to cash collection — and the idea most people skip over inside it: when is revenue recognised, and what does that have to do with the moment goods leave the warehouse?