DAX Cumulative Total Comparison from Different Tables - powerpivot

Question

How do I create a DAX measure that will show me the First Receipt Date where the Receipt Balance is greater than or equal to the Payment Balance?
For example, for Jun, I want the [Payment Receipt Date Avg] measure to show as Jan because the Receipt Balance is 10 which is greater than the Payment Balance of 8.
For Aug, it would show as Feb because that is the first date where the Receipt Balance is at least the Payment Balance of 13.
Desired Result:
Data Model
Table: Po Receipt
Table: Payment
Attempted Solution
I already have the below measures defined:
Receipt Balance:
=CALCULATE
(
SUM(PoReceipt[Quantity Received]),
FILTER
(
ALL ( PaymentDates ),
PaymentDates[Payment_FullDate] <= MAX ( PaymentDates[Payment_FullDate] )
)
)
Payment Balance:
=CALCULATE
(
SUM(Payment[Payment Amount]),
FILTER
(
ALL ( PaymentDates ),
PaymentDates[Payment_FullDate] <= MAX ( PaymentDates[Payment_FullDate] )
)
)

Answer 1

Create calculated columns to get the first date which has a net receipt running total (i.e. receipts less payments running total) greater than the payment amount in the current row context. The calculated columns will need to do the following:
Return the running total of [Payment Amount] for each [PO Num]. The EARLIER function is used so that for each row in the outer context, you sum all rows in the inner context where the inner row has a [Payment Date] less than or equal to the outer row, and the inner row's [Po Num] is equal to that of the outer row.
Return a summary table based on the PoReceipt table, which has an extended column "Receipt Balance Calc". The extended column calculates the running total of the PoReceipt[Quantity Received] similar to step 1. The summary table is grouped by the columns [Po Num] and [Receipt Date] to avoid performing the same calculation more than once (since there are multiple rows with the same [Po Num] due to the [Receipt Num] column).
Filter the result to only include rows where the Receipt Balance is greater than or equal to the Payment Balance.
See DAX code for calculated columns:
Payment[Payment Balance Calc]
=CALCULATE (
SUM ( Payment[Payment Amount] ),
FILTER (
Payment,
Payment[Payment Date] <= EARLIER ( Payment[Payment Date] )
&& Payment[Po Num] = EARLIER ( Payment[Po Num] )
)
)
Payment[Payment Receipt Date]
=CALCULATE (
MIN ( PoReceipt[Receipt Date] ),
ALL ( PaymentDates ),
FILTER (
ADDCOLUMNS (
SUMMARIZE (
PoReceipt,
PoReceipt[Po Num],
PoReceipt[Receipt Date]
),
"Receipt Balance Calc",
CALCULATE (
SUM ( PoReceipt[Quantity Received] ),
FILTER (
PoReceipt,
PoReceipt[Receipt Date] <= EARLIER ( PoReceipt[Receipt Date] )
&& PoReceipt[Po Num] = EARLIER ( PoReceipt[Po Num] )
)
)
),
[Receipt Balance Calc] >= EARLIER ( Payment[Payment Balance Calc] )
)
)
Finally, create the below measure to calculate the weighted average of the receipt dates:
Payment Receipt Date Avg:=
SUMX (
Payment,
Payment[Payment Amount] * Payment[Payment Receipt Date]
/ SUM ( Payment[Payment Amount] )
)