calculate/show result in column based on previous result

[Roym]

With some help from this community I have the following Dax code that is doing the following:

1. If the test is effective, and the review is also effective -> Column= Effective

2. If test is effective, and review is Ineffective -> Column = Ineffective 

3. If the test is effective, and the review is Open -> Column = the review result from the previous assessment.

(Review is always prefered above the test result)

This works perfectly in almost all instances. But if you look at the below table, it goes 'wrong' with the last two items of session 5. In both cases the test is effective and the review is open. With the item before that it works as it shows in column 'effective' but as these two don't have a review result (open) for the previous instance it is showing open. But it should show effective. Is there a way to achieve this result?

Column =

var _previosid=MAXX(filter('Table','Table'[session]=EARLIER('Table'[session])&& 'Table'[ID]< EARLIER('Table'[ID])),'Table'[ID])

var _review=CALCULATE(MAX('Table'[Review]),FILTER('Table','Table'[ID]=_previosid))

VAR _result=

SWITCH(TRUE(),'Table'[Test]="Effective" && 'Table'[Review]="Effective","Effective",

'Table'[Test]="Effective" && 'Table'[Review]="Ineffective","Ineffective",

'Table'[Test]="Effective" && 'Table'[Review]="Open",_review)

return if (_result="",'Table'[Test],_result)

[tamerj1 · Accepted solution]

HI @Roym 
Please try

Column =
VAR CurrentTest = 'Table'[Test]
VAR CurrentReview = 'Table'[Review]
VAR CurrentID = 'Table'[ID]
VAR CurrentsessionTable =
    CALCULATETABLE ( 'Table', ALLEXCEPT ( 'Table', 'Table'[session] ) )
VAR PreviousRecords =
    FILTER (
        CurrentsessionTable,
        'Table'[ID] < CurrentID
            && 'Table'[Review] <> "Open"
    )
VAR PreviousRecord =
    TOPN ( 1, PreviousRecords, 'Table'[ID] )
VAR PreviousReview =
    MAXX ( PreviousRecord, 'Table'[Review] )
VAR Result =
    IF (
        CurrentTest = "Effective",
        SWITCH (
            CurrentReview,
            "Effective", "Effective",
            "Ineffective", "Ineffective",
            "Open", PreviousReview
        )
    )
RETURN
    COALESCE ( Result, 'Table'[Test] )

[Roym]

Great, this works perfectly!! Thanks!!