The purge process removes old entries from the history.
Each PowerFactory project has a history where all changes are recorded. The default is to save this history for 7 days.
The purging removes older entries. This keeps the database small.
The purge process does NOT remove any still needed data.

The settings for the purging are project specific and can be adapted on the Storage-page of the projects edit dialog. The default-value for new projects can be adjusted by altering the default project inside the users Settings-folder.

After the clean up of older history entries it is not possible anymore to create versions of the project with a timestamp older than the current date minus 7 days (or if changed, the retention period defined in the projects Storage page).