Result Analysis - Revenue affecting net income/revenue surplus

Hi,

We have a WBS which has RA key of type POC. For this RA key all actual revenues shoulds be recognized as 'revenue affecting net income' (RANI).

But for some reason, revenues for some periods are not getting recognized as RANI. Instead they are flowing to revenue surplus.

RA key configuration is:

RA type: E

Profit indicator: M

Valuation basis: S

On what basis does the system determine whether a revenue is to be recognized as RANI or as revenue surplus?

Regards