SAP BOM Tables Relationship Diagram

The SAP Bill of Materials (BOM) system is integral for managing the components required to manufacture a product. Look no further than this handy table relationship diagram! It lays out the core tables involved in SAP BOMs in a clear, visual way.

Key Tables in SAP BOM

MAST – Links materials to BOMs.
STKO (BOM Header): This table holds the head information for each BOM. Think of it as the overall details like BOM category, number, and status.
STPO (BOM Item): This is where the items or components of your BOM are listed. Each item in your product recipe is recorded here.
STPU (BOM Sub-item): Need even more detail? STPU is for sub-items within a BOM item. Think of nested components or further breakdowns.
STAS (BOMs – Item Selection): This table is interesting! It manages alternative BOMs and links item nodes. Crucially, it connects BOM items to their alternative BOM options – a key detail often missed!
STZU (Permanent BOM Data): This seems to hold some persistent BOM data – less detail is given on this one, but it’s part of the BOM structure.

Table Relationships

MAST to STKO – Establishes the relationship between materials and their corresponding BOMs.
STKO to STAS – Connects BOM headers to item selection details.
STAS to STPO – Links item selections to specific BOM items.
STPO to STPU – Relates BOM items to their sub-items.

Important Notes

BOM item numbers (STLKN) are internally generated per BOM document.
The data structure follows a four-layer hierarchy: BOM → Alternative BOM → Item → Sub-item.
The relationship between items and alternative BOMs is stored in the STAS table, not in the STPO table.