Notify if an item has a status for a certain amount of time

If something is waiting on a response either from a customer or a colleague, we would set the status to ‘awaiting response’. It would be helpful to have an automation that notifies you if something has been in that status for over a certain amount of time. E.g. if we have been awaiting response for 7 days, then notify somebody so they can send a chasing email. We would require it to work on subitems too.