The optimization process and recommendations:

1. Avoid Correlated Subqueries (query line: 82): A correlated subquery is a subquery that contains a reference (column: SSN_Number) to a table that also appears in the outer query. Usually correlated queries can be rewritten with a join clause, which is the best practice. The database optimizer handles joins much better than correlated subqueries. Therefore, rephrasing the query with a join will allow the optimizer to use the most efficient execution plan for the query.

The optimized query:

WITH fpcRepairs AS (SELECT
        FPC_Row = ROW_NUMBER() OVER (PARTITION 
    BY
        t.SSN_Number 
    ORDER BY
        t.Received_Date,
        t.Claim_Creation_Date,
        t.Repair_Completion_Date,
        t.Claim_Submitted_Date),
        needToChange.idData,
        t.Repair_Completion_Date,
        t.Received_Date,
        fpcRepairs.Work_Order,
        fpcRepairs.SSN_number,
        fpcRepairs.fiMaxActionCode,
        fpcRepairs.idModel,
        fpcRepairs.ModelName,
        SP = (SELECT
            TOP 1 Reused_Indicator 
        FROM
            tabDataDetail td 
        INNER JOIN
            tabSparePart sp 
                ON td.fiSparePart = sp.idSparePart 
        WHERE
            td.fiData = t.idData 
            AND (td.Material_Quantity <> 0) 
            AND (sp.SparePartName = '1254-3751')) 
    FROM
        tabData AS t 
    INNER JOIN
        modModel AS m 
            ON t.fiModel = m.idModel 
    WHERE
        (m.ModelName = 'LT26i') 
        AND EXISTS (SELECT
            NULL 
        FROM
            tabDataDetail AS td 
        INNER JOIN
            tabSparePart AS sp 
                ON td.fiSparePart = sp.idSparePart 
        WHERE
            (td.fiData = t.idData) 
            AND (td.Material_Quantity <> 0) 
            AND (sp.SparePartName = '1254-3751'))), needToChange AS (SELECT
            needToChange.idData 
        FROM
            tabData AS t 
        INNER JOIN
            modModel AS m 
                ON t.fiModel = m.idModel 
        WHERE
            (m.ModelName = 'LT26i') 
            AND EXISTS (SELECT
                NULL 
            FROM
                tabDataDetail AS td 
            INNER JOIN
                tabSparePart AS sp 
                    ON td.fiSparePart = sp.idSparePart 
            WHERE
                (td.fiData = t.idData) 
                AND (td.Material_Quantity <> 0) 
                AND (sp.SparePartName IN ('1257-2741', '1257-2742', '1248-2338', '1254-7035', '1248-2345', '1254-7042')))) SELECT
                t.idData 
            FROM
                tabData AS t 
            INNER JOIN
                modModel AS m 
                    ON t.fiModel = m.idModel 
            INNER JOIN
                needToChange 
                    ON t.idData = needToChange.idData 
            LEFT OUTER JOIN
                fpcRepairs rep 
                    ON t.idData = rep.idData 
            WHERE
                rep.idData IS NOT NULL 
                AND rep.FPC_Row > 1 
                AND (
                    SELECT
                        lastRep.SP 
                    FROM
                        fpcRepairs lastRep 
                    WHERE
                        lastRep.SSN_Number = rep.SSN_Number 
                        AND lastRep.FPC_Row = rep.FPC_Row - 1
                ) = rep.SP 
                OR rep.idData IS NOT NULL 
                AND rep.FPC_Row = 1 
                AND rep.SP = 0 
            ORDER BY
                t.idData