MM / P2Pintermediate

MM Account Determination Part 2: Configuring Valuation Classes, Grouping Codes and OBYC

Key takeaway

Configure the building blocks: valuation control and grouping codes (OMWM/OMWD), account category references and valuation classes (OMSK), and OBYC entries per chart of accounts and transaction key, including rules (which fields the key depends on).

Explanation

📌 KEY POINTS
✅ Valuation grouping code (active via OMWM, assigned in OMWD) lets valuation areas share OBYC entries.
✅ OMSK links valuation classes to material types via account category references.
✅ OBYC: per key, define rules (grouping code, modifier, valuation class dependence) then accounts.
✅ Debit/credit accounts can differ where needed.
⚠️ Changing rules later invalidates existing entries — design rules first.

━━━━━━━━━━━━━━━━━━━━
▶ WHERE WE ARE
Part 1 explained the concept. Now configuration.

━━━━━━━━━━━━━━━━━━━━
▶ 1. VALUATION CONTROL

Activate grouping code; assign valuation areas.

━━━━━━━━━━━━━━━━━━━━
▶ 2. VALUATION CLASSES

Account category reference → classes → material types.

━━━━━━━━━━━━━━━━━━━━
▶ 3. OBYC RULES

Dependencies per key.

━━━━━━━━━━━━━━━━━━━━
▶ 4. OBYC ACCOUNTS

Entries per combination; debit/credit.

━━━━━━━━━━━━━━━━━━━━
▶ 5. TEST AND DOCUMENT

Simulate movements; account matrix document.

━━━━━━━━━━━━━━━━━━━━
▶ STEP BY STEP

Check OMWD for the plant.
Check OMSK for the material type.
Maintain BSX entry for a new class.

✅ CHECKPOINT: a GR for the new class posts to the intended stock account.

Code example

ABAP Code

===== STEP 1: grouping =====OMWM: valuation grouping code active | OMWD: plant 1000 → 0001, plant 2000 → 0001 ===== STEP 2: classes =====OMSK: reference 0001 → classes 3000, 3001 | material type ROH → reference 0001 ===== STEP 3: OBYC =====BSX rules: grouping code + valuation class | 0001/3000 → 300000GBB rules: grouping code + modifier + valuation class | 0001/VBR/3000 → 400000

Real project scenario

A company wanted separate stock accounts for a new plant but used the same grouping code as others. Postings mixed with existing plants. Assigning a new grouping code and maintaining its entries separated accounts as finance required.

Common mistakes

Wrong grouping codes.
Rules changed after entries exist.
Missing classes in OMSK.
Undocumented entries.
No tests.

Best practices

Design rules first.
Use grouping codes deliberately.
Maintain an account matrix.
Test per class.
Sign off with finance.

Interview angle

Questions: "What is a valuation grouping code?", "How are classes linked to material types?", "What are OBYC rules?"
Strong answer: OMWM/OMWD, OMSK, OBYC rules and entries, testing and documentation.

Practice this lesson

Quick check

1. Two plants must post to different stock accounts, but they share OBYC entries. What should be changed?

2. Which configuration object acts as an intermediate link between material types and valuation classes, controlling which valuation classes are permitted for materials of a given material type?

3. Which of the following is NOT typically used as a key field when the system searches for the correct G/L account combination during automatic account determination in OBYC?

Interview questions

1. During configuration for materials using Moving Average Price, how does the automatic account determination in OBYC interact with valuation class to ensure correct GL posting when the stock account balance goes negative or insufficient to absorb a price difference?

Answer it in your own words first, then compare.

2. In OBYC, how does the combination of valuation class and transaction key ensure the correct GL account is derived for a warehouse goods movement, and what configuration elements must align for this to work correctly?