MM Inventory Valuation Part 5: Automatic Account Determination — BSX, WRX, GBB and Valuation Class

Key takeaway

How MM finds G/L accounts: valuation grouping code, valuation class, transaction keys (BSX, WRX, GBB, PRD, UMB, KDM…), account modifiers (e. g. VBR, VAX, VAY, INV), movement type assignment, and how to analyse and fix wrong or missing accounts.

Explanation

📌 KEY POINTS
✅ Keys: chart of accounts + valuation grouping code + valuation class + transaction key (+ account modifier) → G/L account.
✅ BSX stock, WRX GR/IR, GBB offsetting entry (with modifiers like VBR consumption, VAX/VAY sales, INV inventory differences, BSA initial entry), PRD price differences.
✅ Movement types determine transaction keys and modifiers.
✅ Valuation grouping code lets plants share or separate account determination.
⚠️ A missing OBYC entry stops posting; a wrong one posts silently to the wrong account.

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▶ WHERE WE ARE
Part 4 covered split valuation. Now account determination.

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▶ 1. INGREDIENTS

Chart of accounts, valuation grouping code (OMWD), valuation class.

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▶ 2. TRANSACTION KEYS

BSX, WRX, GBB, PRD, UMB, KON (consignment), and more.

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▶ 3. ACCOUNT MODIFIERS

GBB: VBR, VAX, VAY, INV, BSA, AUF...; PRD modifiers per settings.

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▶ 4. MOVEMENT TYPES

Movement type → value string → keys and modifiers.

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▶ 5. ANALYSIS

Simulation in MIGO/OBYC, error messages, document review.

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▶ STEP BY STEP

Take a 201 GI; identify BSX and GBB-VBR.
Check OBYC entries for the valuation class.
Change nothing in production without finance approval.

✅ CHECKPOINT: you can derive the G/L accounts for GR, GI to cost center, scrapping and physical inventory differences.

Code example

ABAP Code

===== STEP 1: determination =====Chart of accounts INT + valuation grouping 0001 + valuation class 3000 + BSX → 300000GBB + VBR (GI to cost center) + valuation class 3000 → 400000 consumptionGBB + INV (physical inventory difference) → 233000 | PRD → 231000 ===== STEP 2: movement types =====101 → BSX/WRX(/PRD) | 201 → BSX/GBB-VBR | 551 → BSX/GBB-VNG | 701 → BSX/GBB-INV ===== STEP 3: analysis =====OBYC display | MIGO simulation | error "account determination for entry ... not possible"

Real project scenario

A 201 goods issue posted to the wrong expense account because the valuation class of a new material group had GBB-VBR mapped to a generic account. Finance identified it at month-end. The team defined OBYC entries for new classes with finance sign-off and tested each movement before activation.

Common mistakes

Missing entries for new classes.
Editing OBYC without finance.
Ignoring modifiers.
Not testing movement types.
Using one valuation class for everything.

Best practices

Document the account matrix.
Test movements per class.
Get finance sign-off.
Use simulation.
Review after new classes.

Interview angle

Questions: "How does MM account determination work?", "What are BSX/WRX/GBB?", "What is an account modifier?"
Strong answer: determination keys, transaction keys and modifiers, movement type link, grouping code, analysis and governance.

Practice this lesson

Quick check

1. A new valuation class was created, and GRs now fail with an account determination error. Why?

2. A 201 goods issue posts to an unexpected expense account. What should be checked?

3. What is the purpose of the valuation grouping code?

Interview questions

1. A user reports that a goods receipt for a purchase order posted to an incorrect inventory G/L account. They suggest changing the movement type to fix the posting. How would you analyze this situation, and what is your response to their suggestion?

Answer it in your own words first, then compare.

2. Goods movements post to unexpected G/L accounts after introducing new material groups. How do you analyse MM account determination?

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.