Create Detached Order Assembly 
Use
You create a detached order assembly if, for example, you have to design, order or assemble certain components, before the design of the whole product is complete. You do not have to decide until later, at which point you want to insert the detached order assembly.
Prerequisites
You have already entered the material, into which you later want to insert the detached order assembly, in a sales order.
Procedure
If the BOM header material that you entered in the initial screen is not available in the multi-level BOM for the sales order item, you see a detached order assembly.
Result
In the order analysis the detached order assembly is shown on the tab page
Detached .
A detached assembly is also created if you