Working with Structures 
Structures serve as a kind of table of contents of a documentation project. They help authors chunk and organize pieces of information in the writing process and make it easier for the reader to navigate through the documentation.
Caution
Until further notice, structure editing is restricted to folders in the classic documentation area of SAP Knowledge Warehouse. You need both a classic and an XML folder for your documentation project, irrespective of whether it is a mixed-format project or an XML only project, and you can do structure editing in the classic folder only. Structures in a classic folder may contain both Microsoft Word and XML content objects.
When you start a new XML only project, the interim solution is:
Create a folder in the classic documentation area of SAP Knowledge Workbench.
Within the classic folder, create a new structure using a Microsoft Word content object as root object.
Replace the Microsoft Word content object with an XML content object. To do so, search for the XML content object in the XML Documentation area.
This figure shows how you can create documentation structures in SAP Knowledge Workbench.

In SAP Knowledge Workbench offline mode, you create the main structure and all content objects that you want to go into the structure. Alternatively, if you already created the structure as well as some of the content objects, you use SAP Knowledge Workbench online mode to check them out:
You check out the structure for editing.
You check out the content objects for display.
In SAP Knowledge Workbench offline mode, you insert new or existing content objects into your structure and move them around using drag and drop.
You may insert both classic and XML content objects into one and the same structure.
Note
With content objects that were converted successfully, it does not make any difference whether you include the Microsoft Word file or the XML file into your structure. In either case, the XML file as the most current file is retrieved since there is a mapping between the Microsoft Word file and the XML file. You do not have to replace the Microsoft Word files with the converted XML files in your structure.
In SAP Knowledge Workbench online mode, you check back in all objects when you are finished.
Structure Editing (in the standard SAP Knowledge Workbench documentation)