To Commit Changes as a Revision

Begin working on your design model and make changes.
Note: If another user has made changes in a model and those changes are not yet committed, you will see an alert box when you open the file. The alert indicates that any uncommitted changes will be assigned to you, the current user.
In the status bar, select Design History and choose Commit from the pop-up menu.
The Commit Changes dialog opens.
Enter a comment to indicate the changes made in the revision.
Click OK.
The revision is committed and the comment appears in the Design History dialog.