Notification on difference between time tracking and estimated time


My company uses the time tracking function to track the time spent by technicians on services.
It would be great if we could be able to send notification if the time tracker reaches a certain level, determined by another column.
Example: I send my technician for a 2 hour service (estimation). His workload is based on these 2 hours. I would like to get a warning as soon as the time tracker as reach these 2 hours. If he stays longer than the forecasted time, he may not be able to complete the services booked for this day. This notification would allow the office to react and eventually rebook some later services.
Would anybody have an idea on how to make this happen in ?
Would an app have this kind of ability ?

Thanks for your answers and suggestions