Which AWS service enables you to monitor equipment fleets for failures or changes in operation and trigger actions accordingly?

• A. AWS IoT Greengrass
• B. AWS IoT SiteWise
• C. AWS IoT Things Graph
• D. AWS IoT Events

Answer: (D)

The idea being tested is detecting conditions across devices and fleets and automatically taking action when those conditions occur. AWS IoT Events is built for this pattern. It lets you define detector models that continuously ingest data from many devices and look for specific conditions—such as faults, threshold breaches, or unusual changes. When a condition is met, IoT Events can immediately trigger actions like sending alerts, invoking a Lambda function, or publishing messages to other services, enabling rapid, coordinated responses across a fleet.

This is different from edge-focused processing, asset data collection, or workflow orchestration. AWS IoT Greengrass runs code and processes data at the device edge, useful for local decisions or offline operation but not primarily for centralized fleet event detection. AWS IoT SiteWise focuses on modeling industrial assets and collecting/analyzing equipment data for dashboards, not the built-in event-detection-and-response workflow. AWS IoT Things Graph provides visual flows to coordinate devices and services, but its strength is workflow orchestration rather than dedicated cross-device event detection with automated actions.