AME: How to redirect an approval notification

Hello, Experts:

We are newly implementing Approvals Management Engine for requisitions.  Before we Go Live, we want to understand what technical tools the analysts have to manage a workflow should a problem arise.

There is a particular case we want to manage:

If a specific document workflow is waiting for a particular approver, and that employee has been terminated or has taken vacation without setting up worklist access, we would want to push that workflow to the next approver.  How would we go about sending the approval request to the next person, and eliminate the requirement for approval from the absent person?