# Digital Twin Interoperability **Domain:** Digital Twins / Systems Integration / Standards **Doc Type:** Canonical Bridge Concept **Maturity:** Developed ## Definition **Digital twin interoperability** is the ability of independently developed twins to exchange state, preserve shared meaning and participate in a larger operational representation without erasing their distinct purposes or authorities. It is more than file compatibility. Syntactic exchange is insufficient if identity, units, time, uncertainty, topology and authority are interpreted differently. ## Historical Lineage Industrial integration, building information modeling, geographic information systems and systems engineering each developed partial models around their own tasks. Digital twins intensify the integration problem because live state and model outputs may drive consequential decisions across domains. ## Governing Variable Interoperability governs meaningful composition: which entities correspond, which states can be trusted, how updates propagate and what use is permitted. ## Material and Computational Manifestation Shared identifiers, semantic models, APIs, event schemas, units, time bases, provenance and access policies create the boundary. A facility twin, grid twin and workload model can contribute to an [[wiki/Aggregated Digital Twin|aggregated twin]] only if their meanings and update rules are compatible. ## Relation to Governance Interoperability permits higher-order capability without requiring one owner to rebuild every lower system. It therefore creates [[wiki/Higher-Order Agency|higher-order agency]] while shifting power toward the layer that defines shared schemas and acceptable representations. ## Constitutional Question and Failure Modes Who defines identity equivalence, which model wins during conflict and whether a subject can correct propagated error are constitutional questions. Failure modes include semantic drift, unit mismatch, stale synchronization, authority laundering and loss of context when a local model is consumed at a higher scale. ## Related Ontology [[wiki/Digital Twin|Digital Twin]] · [[wiki/Semantic Interoperability|Semantic Interoperability]] · [[wiki/System of Systems|System of Systems]] · [[wiki/Operational Representation|Operational Representation]] · [[wiki/Model-Space Sovereignty|Model-Space Sovereignty]]