I want to make a difference between Down (not available) and Alert of sensors of a device. As such we have one Alert created for one Sensor of a device when it is down (Typically PING). For other sensors such as Disk (WMI Free Disk Space) We want a warning in a range from 10-25% and an Alert when Dispace is less than 10%. We do not want a message if the disk sensor is "Down" and has no signal.
The reason is that we only want one message if a machine is down and one if it is up. Next to this we want to have messages if defined ranges or results of a sensor do not meet.
At the moment every down of a machine creates down for every sensor. If you have something like VMWARE host going down its very hard to find your way through the jungle of messages.