Alerts are classified in multiple categories of severity, using a simple, intuitive classification system (that is, "green", "yellow" or "red").
For Overdue, Exception and Notification Alerts, the severity is based on the length of time that has elapsed since the alert was originally raised. These alerts escalate from green to yellow to red as time elapses, assuming the alert scenario is not resolved.
For Violation Alerts, the severity is based on the difference between the scheduled and actual dates/times. These alerts do not escalate. The severity is established at the time the alert is created and is not subsequently changed unless one or both of the dates used as the basis for the alert are subsequently modified.