And how are these tables related to each other?
It will be especially important to see how the Interface table is linked to any of the other tables.
Sorry I should have stated that. I have attached a screenshot of my relationships. Did you need to see the other fields also?
There's not table occurrence in your chart named "interface" yet you have a field from an occurrence of that name in your first post: (Interface::Department)
Unless that field has global storage specified, it would also need to be linked in a relationship here. Does it have global storage?
In your report, what data will you need to use to get your grand summary totals? are you listing multiple projects in a single report, one row to each project? What determines which projects make up your report and which will not be included?
And are you using FileMaker 13, 12 or an earlier version?