I want to be able to notify someone when a timeline, or specifically an end date, is moved beyond a set tolerance. So for example, Agreed end date is X, project tolerance is 10%. If end date goes 10% above agreed end date, then notify Y.
Or if that’s not possible, notify someone when the new timeline end date goes beyond X.
I think you’d need a work around and a boost from a third party app to have a tolerance level set with this the way you are describing it, however, you can get something that may be suitable out of a native automation.
I would look to use something like the below, which can work with timeline dates as shown:
This would allow you to set the time passed the timeline end date that you’d like to trigger the notification, but works in number of days rather that percentage of time.