Here you can add/edit/delete Systems.
The Manage Systems form allows you to add/edit/delete Systems and their descriptions.
Each Item that you add to the Project can be assigned a System to help you stay organized.
You can add/edit/delete Systems.
Many of the reports in SI have Report Definitions set to group by System so it is a handy field to assign to Items within a Project.
Systems within Projects have an additional Notes field for adding internal notes: