This depends on the setting in versioning. By default the setting is
Minor Changes - 001 - Automatically retain progress free of charge
Major changes 002 - Manually delete progress fee paying.
Depends on this setting, the progress will be retained or deleted.
Please check this documentation:
http://wiki.scn.sap.com/wiki/display/ERPHCM/Versioning+Customizing
Regards,
Rahul