Digital Twin-enabled Systems (DTeS) are increasingly relevant in practice, particularly in the context of large, complex, and long-lived industrial facilities, buildings, and infrastructure. These systems are typically composed by orchestrating existing assets using a wide range of technologies and artifacts originating from diverse engineering disciplines. Due to continuous adaptation and evolution of the underlying systems, DTeS are subject to significant change over time, making both their development and long-term maintenance highly challenging.

This paper presents TwinLang, a domain-specific language (DSL) designed to support the modeling and management of DTeS throughout their lifecycle. In TwinLang, Digital Twins can be modeled as code, enabling abstraction, reusability, and integration with software engineering workflows. The DSL supports model transformations as a central concept, which enables refinement from abstract representations to concrete implementations. These transformations also facilitate the projection of models into different views, supporting tasks such as deployment, monitoring, and visualisation.

TwinLang is realised as an internal DSL in Scala, leveraging the language’s expressiveness and strong type system. To illustrate and evaluate our approach, we present the development of a Digital Twin for our AI Lab as a concrete use case.