ZONE

The next level below a SITE is a ZONE. Again, a ZONE 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, related equipment in another, and so on. There can be as many ZONEs owned by a site as required for data organization.

Below ZONE level, the hierarchy is discipline dependent, that means, the elements depend on which discipline you are modeling.