MM / P2Pintermediate

MM Source Determination Part 2: Source Lists and Requisition Assignment

Key takeaway

Configure and use source lists: source list requirement at plant or material level, fixed and blocked sources, validity periods, MRP relevance, generating source lists from agreements and info records, and assigning sources to requisitions automatically or via ME57.

Explanation

📌 KEY POINTS
✅ Source lists (ME01) define allowed suppliers per material/plant with validity.
✅ Source list requirement can be set per plant (configuration) or per material (purchasing view).
✅ Fixed sources are proposed; blocked sources can't be ordered from.
✅ MRP relevance lets MRP assign the source directly to requisitions or scheduling agreements.
⚠️ Mandatory source lists without maintenance block purchasing.

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▶ WHERE WE ARE
Part 1 introduced sources. Now source lists.

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▶ 1. MAINTAINING

ME01 per material/plant; ME05 generate from agreements/info records; ME06 analyze.

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▶ 2. REQUIREMENT

Plant-level (source list requirement) or material purchasing view flag.

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▶ 3. FIXED AND BLOCKED

One fixed source per period; blocked for disallowed suppliers.

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▶ 4. MRP RELEVANCE

1: record relevant (assign to PR), 2: schedule lines for scheduling agreements.

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▶ 5. ASSIGNMENT

Automatic in PRs/MRP; ME57 for manual assignment.

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▶ STEP BY STEP

Generate source lists from contracts (ME05).
Set fixed source and MRP relevance.
Run MRP; check PR assignment.

✅ CHECKPOINT: requisitions for source-list materials get the fixed source automatically.

Code example

ABAP Code

===== STEP 1: maintain =====ME01: plant 1000, material R-100 → 300100 (contract 4600000010 item 10, fixed, MRP 1, valid 2026) | 300300 blockedME05: generate from agreements/info records ===== STEP 2: requirement =====Plant setting: source list requirement (per plant) | material purchasing view: source list flag ===== STEP 3: assignment =====MRP → PR with source 300100 / contract | ME57 for unassigned

Real project scenario

During a rollout at a chemical company, source lists were made mandatory for all plants but migrated only for two. POs failed in the other plants on go-live day. Generating source lists from contracts with ME05 overnight and adding source list checks to cutover validation prevented a repeat in later waves.

Common mistakes

Mandatory lists without data.
Several fixed sources.
Expired validity.
Blocked suppliers not maintained.
No MRP relevance where needed.

Best practices

Generate lists from agreements.
Validate before go-live.
Review validity yearly.
Use blocked entries for disqualified suppliers.
Set MRP relevance deliberately.

Interview angle

Questions: "What is a source list?", "How do you make it mandatory?", "What is MRP relevance?"
Strong answer: ME01/ME05, plant/material requirement, fixed/blocked, validity, MRP relevance, automatic and ME57 assignment.

Practice this lesson

Quick check

1. A team proposes making source lists mandatory for all plants just before go-live. What is the risk?

2. How can source lists be created quickly from existing contracts and info records?

3. What does a blocked entry in a source list do?

Interview questions

1. A purchase requisition configured for automatic source determination is proposing an unexpected vendor, or in some cases no source at all, when converting to a purchase order. Walk through your diagnostic approach across master data and configuration to isolate the root cause.

Answer it in your own words first, then compare.

2. During go-live, purchasers report that certain materials are not defaulting the preferred vendor even though a source list entry exists. Diagnose the likely root causes.