The Bill of Materials or BOM is the object in S/4 HANA where we indicate the Components or Raw Materials required to manufacture a Product.
The Master Bill of Materials must be created before the creation of the Production Order.
When the Production Order is created, the BOM will be copied automatically into it. And from that moment, the changes done to the Master BOM won’t be updated in the Production Order unless it is manually requested so.
It is possible to create different alternative BOMs for the same Product.
For instance, the same Product could be manufactured with different components. Or required different quantities depending on the production process.
BOMs can be used not only for Production, but for other departments or functions, like Engineering, Sales, Cost, …
For that, it is possible to specify their Usage.
The BOMs are structured in:
- Header: Finished or semi-finished goods to be produced
- Items: Raws, components or semi-finished goods which are parts of the Header
- Subitems: Assembly places inside of each Item
At each of the levels, different data is required to be maintained.
BOMs will be also created for semi-finished goods building up complex structures.
BOMs in SAP are defined at Plant level.
So, for the same Material (whether Finished or Semi-finished Good), we can have different BOMs depending on the Plant.
In addition to that, BOMs can be defined for specific purposes (Usages in SAP).
Apart from being able to identify the usage for each of these BOMs, SAP allows to limit the functionality that can be done with each of them.
Production → To use in MRP and Production Orders
Cost → To use only for Costing
Engineering → To use only for Design
Sales → To use only in Sales Orders
In order to be able to create a Bill of Material, all the Materials (Header and Components) must be created for the Plant previously.
In fact, some of the data, as the Material Description or Unit of Measure will be retrieved from the Material Master.