CS01 — Create Material BOM

CS01 creates a bill of material for a material in a specific plant, under a specific BOM usage, valid from a specific date. The structural fact that drives most confusion: a BOM is not owned by the material alone. It is keyed by the combination of material, plant and usage, and within that combination multiple alternatives can coexist with different validity windows. CS01 is strictly a create transaction — it will not open an existing BOM for editing, it will only let a genuinely new material/plant/usage combination (or a new alternative under it) be built. Anyone expecting CS01 to behave like a generic 'go to BOM' entry point will hit an existence error the moment the combination already has a record, and reach for CS02 instead without understanding why.

CS01 is used during initial data setup for a new material that will be manufactured or assembled, and whenever engineering introduces a genuinely new BOM alternative for an existing material in a plant where none exists yet under that usage. It sits upstream of routing creation and upstream of any order type that explodes a BOM: production orders, process orders and MRP planning runs all depend on a valid BOM existing before they can resolve components. A consultant reaches for CS01 specifically at the point of creation; for any subsequent maintenance — adding a component, changing a quantity, extending validity — CS02 is the correct tool, and CS03 for display only. In S/4HANA the same task can be done through the 'Manage Bills of Material' Fiori app, which many production support teams now use in preference to the GUI transaction for day-to-day maintenance, though the underlying create-only restriction is identical.

Start in SE16 on MAST filtered by material number, plant and BOM usage to find the internal BOM number and alternative. Take that BOM number and alternative into STKO to check status, base quantity and validity dates — this is where a wrong or expired validity window shows up. Then filter STPO by the same BOM number and alternative to list the actual components, their quantities and units, and compare those units against the material master unit of measure for each component.

The GUI transaction CS01 and its underlying table structure are unchanged on S/4HANA; no restructuring of BOM data was part of the S/4 conversion. The practical shift is in the front end: the 'Manage Bills of Material' Fiori app is commonly offered as the day-to-day tool for creating and maintaining BOMs, giving a tile-based single-object view instead of the classic screen sequence, but it enforces the same create-versus-change restriction underneath.

This is functional PP or CS master data ownership, not Basis and not ABAP unless a custom validation or user-exit is firing. A clean handover states the material, plant, BOM usage, alternative number, validity date, and the business reason a new BOM or alternative was needed, plus whether engineering change management applies.

CS02 and CS03 are the natural next stops for anyone who has just hit the create-only restriction — CS02 for maintenance, CS03 for a read-only look at what already exists. CS11, CS12 and CS13 explode a BOM multi-level and are the right tool for tracing where a component sits across an assembly structure rather than at a single level. CA01 creates the routing that pairs with the BOM for order costing and scheduling, and is usually the next object touched after a BOM is created for a new material.