A method of optimizing marshalling rail cars into a train at a site and includes determining the track configuration at the site; determining location on the tracks of cars to be marshaled; determining characteristics of the cars to be marshaled; and determining marshalling rules. A calculation is performed to determine an optimum sequence of moves to marshal the cars into a train from the determined track configuration, location on the tracks of cars, characteristics of the cars and the marshalling rules. The resulting sequence is outputted.