The settlement profile contains all the relevant information needed for settling CO orders, sales orders, projects, and production orders.
From the point of view of Profitability Analysis (CO-PA), you need to assign your PA transfer structure to a settlement profile.
The settlement profile must allow profitability segments as settlement receivers. If you want to settle production variances, this must be stored in the settlement profile.
Since the settlement profile is usually entered automatically in the master data of the object being settled (internal order, sales order, or project), you need to specify the desired settlement profile as a default.