I regularly make exports of Warehouse Builder Metadata to files. I do this at least once a day. When there are a lot of changes to OWB objects I make the export multiple times a day. I prefer this over snapshots as these exports to file do not fill up the OWB repository. Regular exports are useful to re-import changed objects and to keep track of changes to your objects.
I have written a script to automatically export Warehouse Builder Metadata. The script can be scheduled via Windows AT command.
Adapt the following to your environment and save as OWB_export.tcl

Now open a command prompt and type:

This will schedule to run the script every weekday at 23:30.