At the moment, users can edit a test which is in completed status.

So, this will cause some issues and make the test setup and the final result inconsistent and incorrect in the worth case.

Proposal

If the test is completed, users should not allow to edit some important fields like the allocation, base conversion rate.

Even better, if we agree to set read-only all fields, then rename or create new action "View test" instead of using the same one "Edit test"