Processing a Single-Level WBS BOM 
Use
You change a WBS BOM with this function.
Prerequisites
You have fixed a material BOM or created a WBS BOM manually.
The same prerequisites apply here as for the processing of material BOMs. For more information, see the component BOM under
Before making a change.
Features
If you create project-specific components in a WBS BOM, you work as you would for processing a material BOM.
You can enhance a WBS BOM by transferring items from an existing WBS BOM or from a material BOM.

Several people can simultaneously process different assemblies of a multi-level BOM. However, a specific assembly can only be processed by one person at a particular time. Therefore, this assembly is locked to other people until it is saved.
The following restrictions apply for WBS BOMs:

After processing a WBS BOM, select
, so that the system can update the current components of a WBS BOM.
Activities
In the context menu of the BOM header, select the command Change or Change with change number.