Zone

The next level below a Site element is a Zone element. Again, a Zone element is not necessarily used to define a physical area, it is more likely to store similar types of item for easy reference, such as a piping system in one Zone element, related equipment in another, and so on. There can be as many Zone elements owned by a site element as required for data organization.

Below Zone level the hierarchy is discipline dependent, that is the elements depend on which discipline the user is modelling.