The Asset Administration Shell is emerging as the standardized digital twin representation for Industrie 4.0 assets, enabling interoperability across organizational and technical boundaries. However, existing access control mechanisms fail to satisfy the Asset Administration Shell’s needs for fine-grained, context-aware, cross-domain security. This paper proposes an access control concept tailored to the Asset Administration Shell, combining Role Based Access Control and Attribute Based Access Control to meet a set of ten key requirements derived from standards, literature, and expert interviews. Our approach follows a technology-neutral architecture, with a concrete prototype implementation using Keycloak as identity provider, Envoy for request interception, and Open Policy Agent for centralized policy based decision-making; thereby separating security concerns from application logic. An evaluation against the defined requirements shows that this prototype meets nine of the ten requirements. Overall, this concept lays the groundwork for future development of secure, scalable, and flexible access control solutions in industrial Asset Administration Shell deployments.

This paper presents a novel approach for the semantic comparison of Asset Administration Shells (AAS), i.e., digital twins within the context of Industry 4.0. As digital twins gain importance in optimizing industrial processes, ensuring interoperability and accurate versioning of AAS becomes critical. We propose a method that focuses on object model-level comparisons rather than mere syntactic differences, enabling a more meaningful assessment of semantic equivalence. Our findings highlight the challenges associated with traditional comparison methods and suggest a comprehensive framework for enhancing AAS versioning and integrity verification.

As Industrie 4.0 (I4.0) technologies continue to advance, ensuring the reliability and robustness of emerging standards like Asset Administration Shells (AAS) becomes paramount. This paper introduces a comprehensive testing approach for reactive (a.k.a. Type 2) AAS implementations, addressing the challenges posed by their intricate and dynamic nature. Our methodology adopts a design-by-contract approach to formalize API behavior. We design the client as a test oracle, where code contracts extensively validate the AAS operations, their interactions and effects. The related test cases cover various operation chains, including superpaths, service specifications, and serialization modifiers. The objective of this approach is to enhance the reliability and effectiveness of testing in the evolving landscape of AAS Type 2 implementations.

The Asset Administration Shell offers the capabilities for unified and interoperable data exchange across the entire life-cycle of an asset. Therefore, using Asset Administration Shells as a data layer is a practical option for facilitating the exchange of information in Simulation-based Engineering. The feasibility of this approach is demonstrated through an implementation, showing that incorporating the Asset Administration Shell as a data layer for standardized data exchange can yield significant benefit for the Simulation-based Engineering process.

The contribution addresses the challenge of transforming a general recipe, which lacks knowledge about specific production resources, into a plant-specific master recipe in the process industry. The authors propose an approach using the concept of capabilities in manufacturing, enabled by an ontology and the Asset Administration Shell. The approach aligns required and offered capabilities at different description levels to allocate equipment to process elements and generate a master recipe in BatchML. The validation of the approach is accompanied by a procedure logic for a modular plant and discusses open challenges. In conclusion, the provided approach offers a methodical and less experience-dependent derivation of a master recipe for a manufacturing process.

The Asset Administration Shell is the key concept for the exchange of asset information in Industrie 4.0 across the entire life cycle of an asset. Therefore, the Asset Administration Shell acts as the central interface to access asset information, which is stored in different source systems, e.g. databases or control units. To achieve this vision, this paper presents the requirements for the standardized integration of data from these source systems into Asset Administration Shell applications and a generic concept for easy and vendor-independent applicability. The concept is demonstrated with two example implementations and evaluated against the requirements.

The digital twin, or more precisely the Asset Administration Shell, is the key element for interoperability in Industrie 4.0. Together with the asset, it forms the I4.0 component. For the development of I4.0 components, the availability of suitable software development tools is becoming increasingly relevant. However, it is not yet specified how these tools are to be systematically tested for correctness, compliance and conformity. These topics are the focus of this work. We show different established testing methods, evaluate their suitability and describe an approach for a capable test environment.