A "service failure" or an "out of service" failure?
If you were a dispatcher a service failure would mean that you failed to deliver a product on time, there was "down-time" or the load was not delivered at all
As a driver, if you had a "service failure" not involving the D.O.T., it would mean that somewhere along the line, in the process of delivering your load, you caused a problem for their customer during the delivery, or even the pickup.
An "out of service" failure would have something to do with a mechanical problem on the truck or your logs, but a logbook issue is usually called an "H.O.S" failure. Hours of Service...
So, in essence, I suppose you may need to be more specific?