Year end calculation and True Ups scenarios in EPCM

Summary:

Scenario: Apart from monthly calculations from Jan to Dec for a year(12 times execution per month), we have a year end calculation process which has also December data as source. Calculation involves a step where true up of previous month outputs are taken to find allocation amount.

e.g.: If actual total cost to be allocated at year end is 20000 and sum of cost allocated already during each month calculation using forecast values(Jan to Dec) is 16000, then, additional cost to be allocated is 4000 (=20000-16000).

Queries:

1. If you have similar kind of scenario, how should we load year end data? If we load it as Dec, won't it get summed up with actual Dec balance?