Checkbox ‘Rewriteable’ allows to overwrite system provided value with manual intervetion.
If you click F1 on this ‘module’ field, you’ll see a variety of indirect valuation modules provided by vendor. There is a good explanation inside each of them, so I won’t bother you copy&pasting it here.
In the infotype, we can see wage types, which is obvious. If you pay closer attention to the ‘I..’ column, you’ll see onde wage type has no ‘I’ letter. ‘I’ stands for ‘Indirect’ and meaning this wage type is evaluated indirectly by the system. Like on the screen below all wag types are valuated indirectly with their own wage type-specific modules (based on settings from the above) and the only M258 is valuated directly – with a value I entered manually.
Now let’s see how it’s stored in the tables. The same infotype 0008 Basic pay.
If the wage type evaluated by the system it has ‘I’ in IND** columns and no amount value. And vice versa.
Your goal is to point to the developer this nuance if they read tables directly in ABAP (which is a bad BAD practice). SAP Query and other tools/reports/function modules normally call the evaluation module to get time-specific values.
If you need to develop your own wage type evaluation module, create a record with its name in T511IV_MT table, and implement a BADI HR_INDVAL in SE19 transaction.
Very soon I’ll record a video with explanations. Stay tuned and subscribe.