Parent Ticket Workflow Automation Options

We need to be able to close parent tickets when all child tickets are completed, because inversely you can't close the parent ticket until children are done. For us, we use this most frequently with the employee onboarding. But the parent ticket is unused, as the tasks are assigned within the child ticket. The parent ticket is a useless mandatory requirement of the onboarding feature. And it remains open, unassigned and uncategorized, when its children are closed.