NeTEx is primarily dedicated to data exchange, i.e. an XML message format and a protocol are specified. The content model of the NeTEx message structure is based upon the NeTEx physical data model and is derived directly from Transmodel, the CEN Public Transport Reference Data Model developed at a conceptual level and independent of an implementation in any specific technology.
As regards functional domains, NeTEx covers only a subset of Transmodel; the Network Topology, Timing Information, Vehicle Scheduling and Fare Information domains, whereas the full scope of Transmodel is broader, including in addition: Operations Monitoring and Control, Fare Management ( sales, validation, control), Management Information and Statistics, Driver Management: Driver Scheduling, Rostering, and Driving Personnel Disposition.
The Transmodel conceptual model is broken down into modular packages with a mostly linear dependency graph between modules. The same organisation of packages is used in the Phsyical model and XML schema so that there is a direct correspondence between the modules for each functional domain. This makes it straightforward to relate the high level design to the implementation.