Collaborative Modeling of Interoperable Digital Twins in a SoS Context

In an Industry 4.0 compliant production plant components from different value chain partners must work together. Digital Twins (DTs) are an essential part of that system of systems because all relevant assets will need those digital representations to be integrated into such kind of environment, as they establish the required flexibility for formerly rigid structures. This does not begin at the time of delivery of products but already during engineering of the production plant, where relevant data and information are needed. The DT topic is not exclusively a software topic, as it cannot be considered without the associated physical twins. This leads to a need for a holistic Model-Based Systems Engineering approach that integrates all necessary aspects into an architecture for interoperable DTs. This contribution presents an approach and guidelines for modeling DTs based on industry use cases. The goal is to support the implementation of interoperable DTs in Industry 4.0 by using formal modeling techniques. This closes the gap between informal discussions about DTs between value chain partners and the implemented interoperable DTs needed for a specific use case. Compatibility with emerging standards such as the asset administration shell is assured. Focus is the modeling of the DT environment, e.g. a production plant as a system of systems as well as the description of logical DT content elements. Main elements in the environment of a DT are other linked DTs, their relationships and interactions. Users of the modeling approach are developers or management responsible for the company's DTs. They can use it to develop the correct DTs for relevant use cases of their assets.