>>> Regarding the vehicleOperator, I would think that binding to trainPart
>>> should be possible for the case that at a certain planning stage,
>>> formations are abstract but the assignment to the operator is already
>> I see, we talk about different "vehicle operators". I try to clarify my
>> point of view. Please, correct me, if I mix other contract bindings
>> * The "vehicle operator" in the Rollingstock sub-schema should be the
>> company that is the "owner" of the vehicle.
>> * The "vehicle operator" in the Timetable sub-schema may be the company
>> that provides the transport service with the vehicle.
>> Such a use case with different wagons and locos did happen at the
>> beginning of this timetable period in December 2012:
>> RE4 of the ODEG: 
>> The wagons and loco of this "fixed formation" had different "vehicle
>> owners", but are operated by one "vehicle operator" for this service.
> Indeed the real world provides a nice example. I suggested  the