Time difference between different rows and columns for tasks with the same parent id

Hi Anonymous,

Based on my test, you could refer to below formula:

Create this measure:

Measure =
VAR M =
    CALCULATE (
        MAX ( 'Table1'[Date Completed] ),
        FILTER ( ALL ( 'Table1' ), 'Table1'[Parent id] = MAX ( 'Table1'[Parent id] ) ),
        FILTER (
            'Table2',
            'Table2'[Department Assigned] = "Kitchen"
                || 'Table2'[Department Assigned] = "Room Service"
                || 'Table2'[ Department Completed] = "Kitchen"
                || 'Table2'[ Department Completed] = "Room Service"
        )
    )
VAR N =
    CALCULATE (
        MIN ( 'Table1'[Date Assigned] ),
        FILTER ( ALL ( 'Table1' ), 'Table1'[Parent id] = MAX ( 'Table1'[Parent id] ) ),
        FILTER (
            'Table2',
            'Table2'[Department Assigned] = "Kitchen"
                || 'Table2'[Department Assigned] = "Room Service"
                || 'Table2'[ Department Completed] = "Kitchen"
                || 'Table2'[ Department Completed] = "Room Service"
        )
    )
RETURN
    IF ( M = MAX ( 'Table1'[Date Completed] ), DATEDIFF ( N, M, MINUTE ), 0 )

Result:

You could also download the pbix file to have a view.

Regards,

Daniel He