The Project Product Structure can be maintained in the Project Item/Consist Of window.
Creating: When connecting new items in the structure, you first have to choose what kind of item you want to connect – a project item, or a standard part, then choose one of the available parts.
Modifying: Some fields can be modified.
Removing: When disconnecting the project item, the part location, tag number, and activity sequence fields are set to null. Disconnected items are not deleted and will exist as items in the delivery project (Project Product/Parts) without a parent item.