CS13 — Where-Used List for Material in BOMs

CS13 answers the question 'where is this material consumed as a component'. Given a material number, it returns the list of BOMs (by header material, plant, BOM usage, and alternative) in which that material shows up as an item. It is a display-only reporting transaction; it does not write to any BOM table and has no change documents of its own. The structural fact that explains most confusion: the result set is not a simple search of STPO for a matching component field. It is filtered by BOM usage, plant, alternative BOM, validity date, and status, exactly the same filters that govern normal BOM explosion. A material genuinely used in a BOM will silently drop out of the where-used list if any one of those selection parameters does not match, which makes CS13 look wrong when it is actually behaving correctly against a narrower selection than the user intended.

CS13 is reached for before making a change to a component material: before setting a deletion flag, before a material number change project, before a specification or unit-of-measure change, or before an engineering change order is released. Production engineers and BOM maintainers run it to identify every parent assembly that would be impacted, then decide whether the change needs to ripple through costing, MRP, or purchasing. It is also used during plant rollouts to confirm a component has been assigned into all the BOMs it should appear in for the new plant. It is not the tool for checking current stock or open requirements for that material; MD04 covers that. It is not the tool for viewing the BOM structure itself in detail; that is CS03. CS13 is purely the reverse lookup, component to parent.

To confirm a component's real usage independent of the transaction's filters, query STPO for rows where the component material field matches, note the internal BOM number and item validity dates on each hit, then join to STKO on that BOM number to read the usage and overall header validity, and to MAST to recover which material, plant, and alternative BOM that header belongs to. Compare the item and header validity ranges against the date entered in CS13; a hit missing from CS13 but present in STPO almost always falls outside one of those ranges, or its deletion indicator is set.

CS13 continues to work unchanged on S/4HANA; it remains part of the classic BOM transaction set and the underlying tables and filter logic are the same. Newer BOM management Fiori apps provide similar where-used capability inside a consolidated BOM maintenance experience, but the classic transaction is still the fastest single-purpose lookup and is commonly the one still used for quick impact checks before a change.

This is a PP/PE master data problem, owned by whoever maintains bills of material for the plant in question. ABAP involvement is limited to custom reports built on top of the BOM tables. A good handover includes the material number searched, the plant, usage, and date parameters used, and whether the expected parent BOM was confirmed to exist by direct table check rather than by the transaction alone.

CS03 is the natural next stop to see the full structure of any BOM surfaced by CS13, including item-level validity and deletion flags. CS01 and CS02 are where the underlying BOM gets created or corrected once the where-used check identifies which parents need attention. CS11 and CS12 run the explosion in the opposite direction, from parent down to components, useful for confirming a fix after a component change. MD04 is worth checking afterward if the where-used result reveals a component change that affects open production or purchase requirements.