Do you know which reports are being used?

<introEmbed body={<> SSRS keeps track of each report that gets executed and records useful information like: - How long did the report take to generate - Who requested the report - When was the report generated - Report Parameters used So it's quite simply a matter of querying the ReportServer database for information in the ExecutionLog table. </>} />

WITH RankedReports
AS
(SELECT ReportID,
        TimeStart,
        UserName,
        RANK() OVER (PARTITION BY ReportID ORDER BY TimeStart DESC) AS iRank
   FROM dbo.ExecutionLog t1
        JOIN
        dbo.Catalog t2
          ON t1.ReportID = t2.ItemID
)
SELECT t2.Name AS ReportName,
       MAX(t1.TimeStart) LastAccessed,
       --t1.UserName,
       t2.Path,
       SUBSTRING(t2.Path, 0, CHARINDEX('/', t2.Path, 2)) ParentFolder,
       t1.ReportID
  FROM RankedReports t1
       JOIN
       dbo.Catalog t2
         ON t1.ReportID = t2.ItemID
 WHERE t1.iRank = 1
GROUP BY t2.Name, Path, ReportID
ORDER BY MAX(t1.TimeStart) DESC;

The query above gives you the last reports that were accessed (Credit to Eric Phan - SSRS - Find out which reports are being used (handy for migrating only the useful reports to a new server))