Estimated Delivery date based on cumulative count

learner03 The blanks come in when there is not enough product coming in from purchase orders to fulfill the request. Therefore, no estimated delivery date. I will check the calculations to see where things are coming from.

learner03 OK, the issue was the sort order of the purchase orders coming in. So, needed more complex DAX to convert the rows to a sorted string and then back to a table. Such a pain but the only way I know in DAX to guarantee ordering. So, the same while loop, just added code for the conversion to a sorted string and then back to a table. Updated PBIX attached.

Column = 
    VAR __DaysToFulfill = 10
    VAR __ItemCode = [Item Code]
    VAR __Date = [Date]
    VAR __QtyToFulfill = SUMX(FILTER('BackOrders',[Item Code] = __ItemCode && [Date] <= __Date),[Backorder Qty])
    VAR __SortedString = CONCATENATEX(FILTER(ALL('OpenPurchaseOrders'),[Item Code] = __ItemCode), [ETA W/H] & ":" & [Quantity], "|", [ETA W/H])
    VAR __Table = 
            ADDCOLUMNS(
                ADDCOLUMNS(
                    GENERATESERIES(1, PATHLENGTH(__SortedString),1),
                    "__row",PATHITEM(__SortedString,[Value])
                ),
                "__date",
                        VAR __Colon = FIND(":", [__row],)
                    RETURN
                        DATEVALUE(LEFT([__row],__Colon -1)),
                "__qty",
                        VAR __Colon = FIND(":", [__row],)
                        VAR __Len = LEN([__row])
                    RETURN
                        VALUE(RIGHT([__row], __Len - __Colon ))
            )
    VAR __Table1 = 
        ADDCOLUMNS(
            ADDCOLUMNS(__Table,"__tqty",SUMX(FILTER(__Table,[__date] <= EARLIER([__date])),[__qty])),
            "__LoopCounter",[__tqty] - __QtyToFulfill
        )
    VAR __TargetDate = MINX(FILTER(__Table1, [__LoopCounter] >= 0),[__date])
    VAR __FulfillmentDate = IF(__TargetDate = BLANK(),BLANK(),__TargetDate+__DaysToFulfill) 
RETURN
    __FulfillmentDate