Can a user be warned if a file is checked out?

I have been asked to implement a feature wherein a user will receive a warning if the close a SW file or close the SW application and the file they were working on has not been checked in yet.  There is concern that a user might leave for a two-week vacation and still have files checked out.

How do others handle this situation?  Is an add-in required?

SolidworksSolidworks Pdm enterprise Pdm