4.6C to ERP 2005 upgrade: OM functionality testing

We are preparing for system upgrade from 4.6C to ERP 2005, and my concern is the Org.Management submodule.

Gurus, please help me with a testing plan (for testing the OM functionality, preferably in MySAP ERP 2005).

Your guidance will be very appreciated in identifying key areas that should be tested in the upgrade, how that testing should look, and perhaps somebody could send to me a list of test cases.

Points will be granted.

Thanks in advance!

Tatiana