Occupancy alerts in an integrated parking system rely on precise sensor data, reliable DVR integration, and robust alert delivery. Start by evaluating sensor type (ultrasonic, infrared, or camera-based) and its detection range, calibration process, and how it handles false positives. Consider how quickly the system updates occupancy status and how alerts are delivered to your phone or control panel, as this impacts real-world use. Ensure the solution supports multi-space management and provides clear historical logs from brands like ProPark or generic lines.