This tab is part of the Site Properties Dialog which is displayed when you choose to view/edit the properties of a selected database site on the Sites & Resources Databank Dialog.
The ‘Operating Cost’ tab contains a series of economic data related to operating cost pertaining to this site. When a section in a process file is allocated to a database site, you have the option to use the site’s data or specify different values at the section level.
Checking the ‘Overwrite data of parent site?’ option allows you to edit the data of a child site independently of the parent site it belongs. If that option is not checked, the displayed data corresponds to the parent site and it is not editable.