If the train you intend to catch is cancelled before it reaches your origin station, the algorithm will use the tap-in data to determine that you could have caught that service. Then, using the tap out data, it will determine the subsequent train you caught.
The system will then work out the delay as the difference between the scheduled arrival time of the cancelled service(s) and the actual arrival time of the train you caught.
Similarly, if the train you are on is cancelled during its journey, the algorithm will use the tap-out data once more. By doing so, it to determine the service you subsequently caught, calculating the delay as the difference between that train’s actual arrival time and the scheduled arrival time of the original service.
In both these instances, the c2c Train Travel app will show the train the algorithm believes you were on for the final part of your journey. The length of delay to that train will be displayed at your destination; however, the compensation value will include credit based on the scheduled arrival time of the cancelled train.