Send an email or other type of notification to dispatch when it's apparent that the technician will not make it to the next call within the arrival window. 

For instance: a setting in the system that would trigger a notification when a tech is still in "arrived" status for a previous call within [X] minutes of the end of the next call's arrival window. 

The [X] should be customizable.  The setting should be applicable to specific arrival windows (we have some arrival windows that we do not want notification on and others that we do) so the setting would be best placed within the setup page of each individual arrival window.

Taking this one step further, it would also be nice if it could also trigger a "late" notification to the customer to send an email and text with a customizable message.