Prioritize Based on Need with Running Totals

[mossmic1]

I am trying to create a priority ranking for POs based on the number of cases needed by Produce. The scenario can have the Product across multiple POs. I want to assign priority (in numbers: 1,2,3,etc) based on the most Cases Needed being the highest priority, but assign no priority once the running total of PO Cases exceeds the needs. So in the tables below, Product A is the highest priority with 4200 cases needed, and POs 111 and 222 should be assigned highest priortity to fill the need, but PO 333 would no longer need priority because the need is filled. Is there any way to write this in DAX to make this happen?

Product	PO	Cases
A	111	3000
A	222	1500
A	333	600
B	444	2000
B	555	2000
C	666	1000
C	777	1000
C	888	1000
C	999	1000

Product	Cases Needed
A	4200
B	4100
C	2000

[v-ljerr-msft · Accepted solution]

Hi @mossmic1,

If I understand you correctly, you should be able to use the formulas below to create three calculate columns get your expected result in your scenario. 

1. Rank PO in Product level.

Column 1 = 
VAR c = Table1[Cases]
RETURN
    CALCULATE (
        RANK.EQ ( c, Table1[Cases], DESC ),
        ALLEXCEPT ( Table1, Table1[Product] )
    )

2. Running total of Previous Rank PO cases.

Column 2 = 
CALCULATE (
    SUM ( Table1[Cases] ),
    FILTER (
        ALL ( Table1 ),
        Table1[Product] = EARLIER ( Table1[Product] )
            && Table1[Column 1] < EARLIER ( Table1[Column 1] )
    )
)

3. Final Rank,

Column 3 = 
IF ( Table1[Column 2] <= RELATED ( Table2[Cases Needed] ), Table1[Column 1] )

Regards

[mossmic1]

This works! Thank you!