Hi David,
Creating a project in Business Analyst Web, automatically creates a group. Groups are the sharing mechanism of ArcGIS Online that allows all the project content, such as sites, reports, point layers, and other items to be combined. Groups also allows for easy collaboration with other users in an organization on the project and makes them available for use in Story Maps, ArcGIS Online, Collector and other ArcGIS apps.
The group is a requirement of the BA project and if deleted will create a corrupted project that will no longer be accessible. Careful consideration should be given before deleting a project.
Thank you for using Business Analyst Web,
Donna