Prior to a project having its status change to Completed, all tasks should be in the Invoiced status. This will indicate the tasks have been finalized and reviewed. When a task has been Invoiced, this information will appear in Cost Info. Using the Actions button will finalize a project and change its status to Completed.
The Actions button is located inside a project on the upper right hand side. When a project is Completed, you cannot add any additional tasks. You may not remove any task from Tasks Lists from a project that is Completed.