Conduct an Exam
Conduction begins at Visible from and ends when the last student's working time is over. Students can open the start page from the moment the exam is visible, and reach the exercises from Start of working time. Once a student submits, their submissions are final.
There is very little to do during conduction itself, which is the point of the checklist and the test run. What you do need is a way to correct a mistake in an exercise while students are working on it.
Updating an Exercise during the Exam
Programming, modeling, text and file upload exercises can be edited mid-exam. Open the exercise and choose Edit. At the bottom of the edit page is a field for a notification text, which Artemis shows to every student currently sitting the exam — so the correction reaches people who have already read the old wording.