There are two types of reports found in the System Integration Assignments section in the Admin/Config menu that show who has what integration assignments and who does not have the integration assignment set.
Use the Quick Search or Advanced Search to find the group of people you want to review.
To see all the integration assignments for the selected people, click on the Integration Summary button and the report will show you the assignments by system.
If you want to see if everyone has an integration assignment for a particular system, select the system from the System dropdown list at the top right and click the Exception Report button.