3 respostas
There is no perfect answer for this but here are a couple things I do.
1. Share the report of reports you would like to delete with your users. I would set the filters such that less than 2,000 are displayed so users can easily see all of the results without exporting the report. If you have 11,000 you might have to do this process several times, maybe by starting with the very oldest reports. Display the "Created By" and "Last Modified By" fields on the report for sure (plus whatever else you want, of course). Ask users to view the report and let them know you will be deleting the reports soon. Users can then search the report for their name to see if they have created or modified any reports that they want to keep. The user simply running the report will remove it from your list of reports that haven't been used recently so they don't even need to contact you about any specific report they want to keep. After a certain time period (couple weeks or so) they should be fair game to delete. One downside of this method is that if someone views a report to see what it is, then of course it will have been run recently and won't show up on your report. In my experience though, this doesn't happen much.
2. If you find folders full of reports that haven't been used, i.e. you find a folder with 30 reports in it and all 30 are old, I will sometimes remove all sharing from the folder, and/or append something like "To Be Deleted" at the end of the folder name. Then, you can see who complains. If no one does you are likely safe to delete the folder and all the reports it contains. Note with this method, if a dashboard depends on those reports, the dashboard will stop working until you share the folder again. A dashboard which uses reports does not cause those reports to show up as having been run recently.
Good luck.