MM / P2Pintermediate

MM Purchase Requisition Part 2: Source Determination for PRs — Source Lists, Quotas and Info Records

Key takeaway

How a supplier gets assigned to a requisition: sequence of quota arrangements, source lists (fixed sources), outline agreements and info records; manual versus automatic source assignment; regular supplier indicators; and what blocks automatic assignment.

Explanation

📌 KEY POINTS
✅ Source determination checks quota arrangements, then source lists (fixed sources), then contracts/scheduling agreements and info records (with regular supplier flag).
✅ Automatic source determination can be set on the PR (or MRP settings) so PRs get a supplier on creation.
✅ Source list requirement at plant or material level restricts suppliers to valid entries.
✅ Multiple valid sources without a fixed source → PR stays unassigned for buyer decision.
⚠️ Blocked sources, expired validity and missing info records are the most common causes of unsourced PRs.

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▶ WHERE WE ARE
Part 1 covered the PR. Now how it gets a supplier.

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▶ 1. SEQUENCE

Quota arrangement → source list (fixed) → contracts/scheduling agreements → info records.

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▶ 2. AUTOMATIC ASSIGNMENT

PR indicator "automatic source determination" / MRP source list relevance.
Single valid source assigned automatically.

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▶ 3. SOURCE LIST CONTROL

Mandatory source list; fixed and blocked entries; validity.

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▶ 4. MANUAL ASSIGNMENT

ME57 assign and process requisitions; Fiori apps for buyers.

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▶ 5. EXCEPTIONS

Several sources, no source, blocked supplier, expired conditions.

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▶ STEP BY STEP

Create info records for two suppliers.
Create a source list with one fixed.
Create a PR with automatic source determination.
Remove fixed flag and repeat.

✅ CHECKPOINT: you can predict whether a PR gets a supplier automatically.

Code example

ABAP Code

===== STEP 1: master data =====ME11 info records: 300100 (price 12.00), 300200 (price 12.50)ME01 source list: 300100 fixed, 300200 not fixed | MEQ1 quota (optional) ===== STEP 2: PR =====ME51N with "Source determination" flag → supplier 300100 assigned ===== STEP 3: manual =====ME57: list unassigned PRs → assign sources → create POs

Real project scenario

A buyer manually chose Supplier A for PRs, but nightly MRP regenerated requisitions with Supplier B because a quota arrangement allocated B. Buyers kept correcting. Aligning the quota arrangement with the negotiated split and training buyers on source precedence stopped the conflict.

Common mistakes

Ignoring quota precedence.
Several fixed sources.
Expired source list validity.
Info records without regular supplier logic.
Manual assignment as default.

Best practices

Maintain one fixed source per period.
Keep quotas aligned with contracts.
Monitor unsourced PRs.
Refresh validity dates.
Automate assignment.

Interview angle

Questions: "How does SAP determine a source for a PR?", "Why is a PR unsourced?", "What is a fixed source?"
Strong answer: sequence quota → source list → agreements → info records, automatic flag, source list requirement, fixed/blocked, manual assignment via ME57, exceptions.

Practice this lesson

Quick check

1. A PR stays without supplier although info records exist for two suppliers. What is a likely reason?

2. A buyer assigns Supplier A, but MRP regenerates PRs with Supplier B. What should be checked?

3. Which transaction lets buyers assign sources to open requisitions and create POs?

Interview questions

1. Many requisitions stay unsourced and buyers assign suppliers manually. How do you improve automatic source determination?

Answer it in your own words first, then compare.

2. In a Central Procurement hub scenario connected to multiple S/4HANA Public Cloud execution systems, sales order-driven third-party purchase requisitions from an SD-integrated execution system are not appearing in the central procurement worklist. How do you troubleshoot this?

Answer it in your own words first, then compare.

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Reference-verified: the steps are checked against official SAP documentation and tutorials, and object and field names in the sample code are checked for consistency. The code has not been compiled or run on an SAP system by ERPClimb. Syntax marked release-dependent varies by SAP release, so check it in your own system.