Google Apps Admins have access to a really powerful reporting for Google Drive, that not very many people know about. Docs Auditing, which is disabled by default, allows Admins to see whenever a Doc has been viewed or edited.
Admins can enable Docs auditing in the Google Apps Admin Console, which we cover in this video. Once you access the audit log, it can be filtered by date so you can easily target a certain event. Admins can determine which user interacted with the Doc, and what type of action they took (viewed or edited).
Unfortunately, this tool is somewhat limited as it only applies to Docs (not Slides, Sheets or other Drive files), but it is definitely useful if you have important files that you want to monitor.
To enable Docs auditing in the Google Apps Admin Console:
1. Sign in to the Google Admin console
2. Click Google Apps, then Drive, then General
3. Scroll down to the Docs auditing section and check the box to Enable document audit.