IIC Journal of Innovation 2nd Edition | Page 66

Industrial Internet: Towards Interoperability and Composability them to interconnect to and interact with each other directly to enable autonomous collaboration among themselves to solve problems locally. As a result, the existing point-to-point interconnect patterns will give way to a meshed many-to-many ad hoc interconnectivity. Given the large variations in the types of the CPSs expected to be involved in such interactions in a deployment, the interoperability problem multiplies. This multitude of interactions among the industrial assets raises a unique quantitative challenge in interoperability that we expect to face in the Industrial Internet. A new class of cross-industrial sector connectivity frameworks such as Data Distribution System (DDS)31 and OPC-UA32 are expected to be seen increasingly deployed not only providing the needed interoperability in communication, connectivity and data modeling but also scalability, performance and security as well. Moreover, consider the many unique characteristics that are present in industrial systems, including:  produce physical effects  strong safety requirements  often mission-critical  subject to dynamic conditions and operate in environments that are not always foreseeable at the design time  long lifecycle, being very costly or even impractical to replace on demand  advancement towards autonomy, increasingly capable of learning and making decisions based on conditions without intervention All of these pose a qualitative challenge in interoperability in how to ensure the correct outcomes in these interacting systems under changing conditions and dynamic environments. This challenge calls for a higher level of interoperability: composability, as highlighted at the introduction of this article. Adding to these quantitative and qualitative interoperability challenges is the dynamism of the system within itself concerning how to sustain the required level of interoperability as the interacting components evolve over time in their respective lifecycles and as new components enter into the system. To address these issues, it may be beneficial to reference the IT/Cloud Computing world where the Service Oriented Architect ure (SOA) paradigm has matured and is widely adopted in software design. Within this design paradigm, self-contained units of software capability are encapsulated as services and exposed through service interfaces, often in the form of APIs (Application Program Interfaces) that can be invoked remotely through a network. This allows software capabilities to be loosely coupled (allowing independent evolution, among other things) and large software capabilities can be assembled from a set of cooperating services 31 http://portals.omg.org/dds/ 32 https://opcfoundation.org/about/opc-technologies/opc-ua/ IIC Journal of Innovation - 65 -