Project Active/Archived - used to set project completed?

Project Active/Archived - used to set project completed?

While archiving some of our projects I noticed that when I set a project to Archived, it actually set's the project status to 'Completed'.
I have noticed before that even though all tasks/tasklists/milestones are completed, the project is not set to completed (even though it is 100% done).

If archiving is meant as a project completion flag that would be really confusing, as I might not want to archive a project that was just completed right away. But it would be good to have somewhere an actual completion data (either determined from 100% asks/tasklists/milestones completion or be having an extra option for completed in the active/archive selection.

Thanks,
menno