The case to solve:

Recalculate IM for period before current month or current month -1.

Reminder, Integrated Margin is calculated in WBP with program Z_M_INT in process chain PC_INT_MARGIN.

The data are loaded in chain RSP_COPCP_MONTHLY (WBP) and PC_CO_PC_MM_04 (CPX).

Chain PC_CO_PC_MM_04 (CPX) begins at the end of chain RSP_COPCP_MONTHLY (WBP) and chain PC_INT_MARGIN begins at the end of PC_CO_PC_MM_04 (CPX).

It's possible to reload specific previous month with help of TVARVC table (in WBP system and WPX system):
By default, in table TVARVC for name "Z_PERIOD_IM_HIST", the LOW field should be empty.
If this field is empty, the decisions in process chains will choose the current period and / or current period -1.

If the LOW field is not empty, the process chains will use this month to calcul the integrated margin. 


So, to reload historical data it's necessary to update TVARVC table with one period in format MMMYYYY.
Execute process chain RSP_COPCP_MONTHLY.
When it's done, if necessary update another period in TVARVC table and execute again the chain to calcul another period.
Don't forget to clear LOW field in TVARVC table for the nexts runs of process chains.