There is no such direct mapping table, cross-table or Function module that describes how the Qualitative/Quantative fields are populated.
SAP follows certain mapping to populate the values for these fields this can be cheked in SCN for Qualitative and Quantitative control indicators mapping.
Secondly to update these indicators in Inspection plan load, you can use the STEUERKZ field value from QPMK table.
This field is concatenation of the 28 control indicators (QMKST structure for Quali/Quantitative fields).
So while uploading the data for Inspection plan, Inspection chracteristics are updated in system first where STEUERKZ can be updated.
Vice versa to know what each indicator value signifies in
the field QPMK-STEUERKZ, we can use the function module QSS0_QMKST_RQMST.
Regards,
Nidhi