Excel Formula to DAX

First, the AND function in DAX accepts only two (2) arguments.  You can't write that in that manner.  Change your code to something like this:

AND(
        [CREATION DATE < 6 MONTHS] = BLANK(),
        AND([PLANT_LEVEL_STATUS] = "ACTIVE",
        AND([IS THE LAST INVOICE DATE < 730 DAYS?] = BLANK(),
        AND([STOCK] = BLANK(),
        AND([DOES IT HAVE OPEN SALES ORDERS?] = BLANK(),
        AND([DOES IT HAVE OPEN PRODUCTION ORDERS?] = BLANK(),[DOES IT HAVE ACTIVE PURCHASE ORDERS?] = BLANK())))))
    )

and the second part as:

AND(
            [CREATION DATE < 6 MONTHS] = BLANK(),
            AND([PLANT_LEVEL_STATUS] = "ACTIVE", [IS THE LAST INVOICE DATE < 730 DAYS?] = "YES")
        )