The purpose of Always-On Monitoring is to make sure your Enterprise Manager environment continues to be monitored while Enterprise Manager OMS is down. However, to protect against a single point of failure within the Always-On Monitoring environment itself, the Always-On Monitoring service can be made highly available by adhering to the Enterprise Manager Maximum Availability Architecture (MAA) guidelines. By setting up Always-On Monitoring as a highly available service, you can ensure that targets will continue to be monitored in the event of catastrophic system failure.