Purpose of Supervisor Information on Organizational Data tab

PS 9.2

PS Navigation: Travel and Expenses -> Manage Employee Information -> Update Profile

We currently do not have an ID assigned in the Supervisor Information area of the "Update Profile" / Organizational Data tab.  I'd like to populate this field with the ID of the employee's direct supervisor/manager.

I don't know what this field is used for in the greater scheme of the system and I do not want to adversely effect any existing process by populating this field.  Can anyone tell me how this field is used and what process (if any) it may impact by populating this field?