We should create PIM's per publicatoins. Users who want to work with the model and are only interested in VMS or parking are bothered with loads and loads of modelparts they are not interested in. (this is a request from the SG Porto 2013)
In DATEX II v3.0, related publications (situation, road traffic data, VMS, parking) will be packaged together and share each one dedicated namespace. The same holds for basic and common data elements as well as location referencing.