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• On the one hand, there is the "conceptual area," where the controlled vocabulary has to be described and adequately documented. Data models belong to this area because they define the entities of interest in a particular domain and the possible relationships between them.
• On the other hand, we have the "application area," where a data model is used in specific implementations (e.g., databases, applications, etc.).

The figure above shows how VSS modeling belongs to the conceptual area. To use the specification described in VSS (i.e., a "vspec" file), one has to parse it into a specific format (e.g., JSON) by using the VSS tools. The tools are the mechanism that makes the VSS data model usable in the application area. From the practical point of view, the application area needs a specific schema that determines the structure in which the data is to be stored. In this context, we mean long-term storage (e.g., a database) or short-term storage (RAM and variables' allocation during application execution).

In the current setup, the whole data model is taken one-to-one and parsed as the schema for the application area. Then, it is up to the specific implementation to use custom mechanisms to ignore the overhead when only some concepts defined in the data model are required or used. Although this aspect has shown no significant limitation until now, it becomes relevant when multiple domains are involved. Therefore, with the increasing interest in adding other domains apart from vehicle-specific data, it is crucial to define a data modeling strategy that can scale beyond tree hierarchies and vehicle-specific data.

Proposal: Unique and standard definitions in the conceptual area with arbitrary selection in the application area

The idea is to center most of the data modeling activities of COVESA into the conceptual area. The conceptual area will be responsible for the standard definition of the controlled vocabulary. The specific aspects of the proposal are illustrated in the following figure, and explained below:

1a - Generic domain tree modelling approach

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