Architecting Digital Twins Using a Domain-Driven Design-Based Approach

The Digital Twin (DT) concept has overcome its initial definition based on a purely descriptive approach focusing on modelling physical objects, often using CAD. Today DT often describes a behavioural approach that can simulate an object's dynamics, monitor its state, and control or predict its behaviour. Although DTs are attracting significant attention and offer many advantages in the design of especially cyber-physical systems, most proposals have focused on developing DTs for a specific use case or need without providing a more holistic approach to its design. We aim to propose a domain-agnostic approach for architecting DTs. Here, DTs are directly supported by Domain-Driven Design's notion of Bounded Contexts (BCs), hiding all the domain-inherent specifications behind BC boundaries. These BCs are also the central abstraction in many microservice architectures and can be used to describe DTs. A Wind Turbine DT architecture is used as a running example to describe how every relevant DT property can be satisfied following our proposal for architecting digital twins. A qualitative evaluation of this case by five external practitioners shows that our DDD-based proposal consistently outperforms the 5-dimension model used as the reference approach.