User Help > Managing Source Files as Members > Deleting a Revision
  
Deleting a Revision
CLI EQUIVALENT 
si deleterevision
If you know you will never use a revision again, you can delete it, provided it is not used in a checkpoint or is not the current member revision of a project configuration.
Note the following:
Only delete a revision when you are certain you will never need it again. Once you delete a revision, it cannot be retrieved. Any historical checkpoints based on a particular revision become invalid if that revision is deleted. A revision cannot be deleted if it is the starting point (root) of a branch. You should never delete the head revision of an archive.
Any existing locks on revisions are removed when those revisions are deleted.
By default Windchill RV&S determines if the revision exists in other locations. If the revision is used in other projects, Windchill RV&S warns you that deleting the selected revision will break the listed items.
To delete a revision in the GUI, select a revision from a Member History view and select Member > Revision > Delete.