I understand that ArcGIS Diagrammer 10.1 is not fully supported, but wanted to caution others who would try to use it with the LGIM xml workspace document. The published xml from Diagrammer is corrupted, or Diagrammer cannot handle some of the objects.
OS/Software
Windows 7 x64
ArcGIS for Desktop Advanced 10.1 SP1 (Build 3143)
ArcGIS Diagrammer v10.0.1
Steps to Recreate
1) Open the 10.1 LocalGovernment.xml in Diagrammer
2) Save as a .diagram file (i.e., LocalGovernment.diagram)
3) Publish to new xml schema file
4) Try to import new xml schema into empty file geodatabase
The publish from Diagrammer works without errors, but I have been unsuccessful in importing it. Errors on that end have varied for me, but the most common was
Import xml data failed
The table was not found. [ParcelFabric_Parcels]
I believe this has to do with a DefinitionClassName associated with the ParcelFabric.
If you open the original LGIM xml in Diagrammer (without saving) and Validate, there several errors and warnings listed right off the bat. I had taken the time to make some changes to some added feature classes and domains for a public safety implementation, and now cannot import the published xml schema into a new geodatabase. Disappointing, but live and learn. Hopefully this will help someone else. I haven't used X-Ray very much, but I guess that's my next option...