Rolling Sum in Member formula

Summary:

12 Months rolling sum to be calculated in member formula

Content (required):

Require a member formula that calculates the prior 12 months' value, Current month + previous 11 months.

Let's assume we are taking value from Account A and calculating the same in Account X(Dynamic Calc).

So far we have been able to achieve it using substitution variables and it works perfectly, except when we change the values of substitution variables. It overwrites the previously calculated value and replaces it with the current value for all prior months.

The logic we have built

This is expectation

This is what happening

When we move to next month