The Need for a Simple Scalable Mechanism
Interoperability is a core concept of computer systems and networks, denoting the ability to discover, connect, and interact with other entities within an application’s broader context. In today’s distributed computing paradigm, efficiently achieving interoperability at all levels of the technology stack is paramount to deriving the most benefit from a system of systems.
For decades, the focus of interoperability has been on making discrete components work in conjunction with one another. The Internet itself is perhaps the best example of billions of devices interoperating at technical and syntactic levels in a truly distributed fashion. At a smaller scale, the dynamic discoverability and capabilities matching of a simple USB is yet another example of the value created through a common interoperability mechanism. The ability to instantly use a device connected via USB with our laptops is an impressive feat of technology that we frequently take for granted.
As we discover new applications of digital twin systems for the betterment of business and society, we become increasingly aware of the importance of interoperability. Ensuring that these systems’ discrete components, as well as the broader system of systems, are interoperable is essential to unlocking their larger potential with less implementation cost, less risk of failure, and less complexity at scale.
A Framework for System Interoperability
In many ways, we are striving to create a framework that would enable USB-type compatibility and ease for all systems connected to the Internet and private networks. Creating a framework to codify and normalize what for years has been relegated to the domain of “system integration” is, of course, a daunting challenge. Most systems were designed to perform specific tasks and typically do not inherently interoperate with entities outside of each system.
The labor-intensive work performed by the $400B+ global system integration industry is often unnecessary. This burden may be eased by designing systems around a common framework and utilizing common mechanism(s) that enable them to interoperate just like USB devices. This would empower those working in system integration to maximize their efforts’ value, designing applications that perform as intended rather than through point-to-point integrations.
The Digital Twin System Interoperability Framework published by the Digital Twin Consortium distills the multiple facets of system interoperability into seven key concepts framing the design considerations necessary to make systems interoperate at scale:
System-Centric Design. Designing products and applications as types of systems simplifies their ability to connect and interact in real-time to form a dynamic system of systems.
Common Metamodel. When all systems share a common metamodel for encapsulating capabilities, purpose, and interface, they become inherently interoperable.
Holistic Information Flow. Information for holistic understanding and optimal decision-making can originate, and must be shared and understandable, across multiple domains.
Stateful Interactions. The state of each system represents information, and changes in state are reflected in the information exchanged among systems.
Federated Repositories. Information must persist and be replicated where needed for optimal decision-making and not be restricted to a centralized repository.
Actionable Information. Shared information must be contextual, trusted, resilient, and read-optimized for timely and appropriate reaction to state changes among systems.
Scalable Mechanisms. Common interoperability mechanisms, embedded within each system, must be simple in design to scale from a single connection and interaction between two systems to a dynamic coalition of distributed, autonomous, and heterogeneous systems within a complex global ecosystem.
A key objective of this framework is to help unify nascent ecosystems of high-value, multi-vendor services that can seamlessly plug into a multi-dimensional, interoperable system of systems. More specifically, it lays the groundwork for building interactive ecosystems of interoperable digital twins.
While the authors may not have contemplated all permutations of system interoperability, evaluating a digital twin perspective within the Digital Twin Consortium has provided the breadth and depth of scope necessary to address this paper’s objectives.
We believe that we have created a framework capable of unlocking significant value in complex distributed computing systems such as digital twins. As we invite you to review, challenge, refine, and adopt this framework, we hope it proves useful in designing computing systems that improve our lives.