"Action Required" checkbox for Owners, Reviewers, Approvers workflow?

Summary:

• Within the areas for an incidents reported (Events, Investigations, and Actions), there is a checkbox labeled "Action Required" for Reviewers, Preapprovers, Approvers, and Owners. Is there a workflow that happens once the reviewer/approver/owner has reviewed their assigned section?
• Does the system automatically wait for the section prior to be completed to notify or allow the next in line to do their analysis of the incident? Similar to a prerequisite. (In sequential order it would be: Preapprovers, Reviewers, Approvers, and Owners.) So far I haven't seen any type of workflow being administered by the system once someone completes their section within the Incident.