SAP Functional, Basis and ABAP Programming Reference Books
Valuation Category

All of the valuation groupings work together. 

You specify whether valuation occurs at plant or company code level in transaction OX14 (Define Valuation Level).  Then whichever one you have defined becomes a Valuation Area.  These areas can be grouped together for ease of account assignment, in which case they become valuation groups.

Account Category Reference codes are associated to material types. 

Valuation Classes are associated to material types in account determination. 

Also an explicit association of Account Category Reference number to Valuation Class is made in Account Determination.

For example,  Material HALB - Semifinished Goods.  Account Category Ref in Material Type is 0008.  Valuation Class 7900 is linked to Account Category Reference 0008.

When a material is created, it is associated to the appropriate Valuation Class on Accounting View 1 of Material Master.

The automatic account determination facility looks up a posting based on the rules defined - whether to look at only Valuation Class, or Valuation Class and an additional Valuation Modifier for BSX postings for example.  It will check the rules, look at the material, material type and valuation area and the rules for the movement itself (where the system is expecting to see the account definitions). All of the definitions need to be consistent.  If you've defined a new Account Category Reference, you need to make sure that's associated to the Valuation Class and Material Type.

The fastest and best way to tell if something is going to post the way you want it to is to simulate the posting.  You can do that in the initial screen with the simulate button.  Choose the plant, the movement type and the system will ask for a material and then tell you where everything will post, or if there's a posting account that is missing.
 

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