Model Fundamentals

A Model is a container that owns a collection of Elements. Every Element is contained by exactly one Model as defined by the ModelContainsElements relationship. Models help organize the overall contents of the repository as there is a separate container for each collection of Elements. The Model contents are driven by:

• The Model subclass
  • Model specializations may limit the types of Elements that can be contained.
• The granularity or level of detail
  • The object as a whole vs. a more detailed breakdown of it
• User preferences
  • Some users may organize by spatial location (east wing vs. west wing) while others may organize by discipline (building vs. civil)
• Domain rules
  • Some rules are enforced by code and are not customizable by users

Core Model Types

Model Identity

Models are also a key building block of the information hierarchy within a BIS repository. Looking down the information hierarchy, Models are collections of Elements. Looking up the information hierarchy, Models are more detail about an Element from a higher level. This higher-level Element is known as the modeled element. The modeled element is what gives a Model its identity. The value of the model's Id matches the value of the modeled element's Id. The Model is related to its modeled Element via the ModelModelsElement relationship. Also, a Model does not store a name of its own. Instead, it its name comes from the CodeValue of its modeled element.

See Information Hierarchy for more details.

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Last Updated: 13 June, 2024