Building system with a building graph

A method of operating a building based on a digital twin of the building, the method comprising:

• causing, by one or more processing circuits, a storage device to store a building graph comprising a plurality of data entities representing a plurality of entities of the building and a plurality of relationships between the plurality of entities;
• retrieving, by the one or more processing circuits, at least a portion of the building graph from the storage device;
• generating, by the one or more processing circuits, derived building data based on at least the portion of the building graph retrieved from the storage device;
• and
• ingesting, by the one or more processing circuits, the derived building data into the building graph.

One or more storage devices storing instructions thereon, that, when executed by one or more processing circuits, cause the one or more processing circuits to:

• cause a storage device to store a building graph comprising a plurality of data entities representing a plurality of entities of a building and a plurality of relationships between the plurality of entities;
• retrieve at least a portion of the building graph from the storage device;
• generate derived building data based on at least the portion of the building graph retrieved from the storage device;
• and
• ingest the derived building data into the building graph;
• wherein the plurality of data entities and the plurality of relationships represent a hierarchy of systems, wherein a first data entity of the plurality of data entities represents a first system, a second data entity of the plurality of data entities represents a second system, and a particular relationship of the plurality of relationships between the second data entity and the first data entity indicate that the second system is a sub-component of the first system.