Deleting an organization does not remove resources, security groups, child organization units, or other entities associated with it. You must have either the Resource Mgmt: Edit Entire Organization or Resource Mgmt: Edit Only Organization Units that I Manage access grant to delete an organization unit.
To remove an organization unit:
Log on to PPM.
Selecting Search > Administrative > Org Units from the menu bar.
The Modify Organization Units page opens.
Select the checkbox next to the organization unit to delete.