To move jobs to the completed list, firstly ensure all Tasks within the job are marked as Completed.
Expand the Jobs menu, then select Outstanding
Highlight the job, then click Tasks
In the Task Navigator window, tick all the outstanding Tasks to mark them as completed.
Once all the Tasks are completed the Job will move to the Completed status.
Note: If the Job has no Tasks started or is no longer required, there is an option to delete the task in the Task Navigator.