A Reference Architecture for Integrating the Industrial Internet of Things in the Industry 4.0

There is an increased attention on propositions on models, infrastructures and frameworks of IoT in both business reports and technical papers. These reports and publications frequently represent a juxtaposition of other related systems and technologies (e.g. Industrial Internet of Things, Cyber Physical Systems, Industry 4.0 etc). At present, the literature is missing a design process for integrating these constantly evolving systems and technologies in a clear and understandable step by step model. This paper contributes with a new reference architecture model for the integration of these systems and technologies. The reference architecture model is based on grouping of future and present techniques and presenting the design process through a new hierarchical framework and a new cascading model. With the application of the grounded theory, the hierarchical framework and the cascading model detail a new process for creating a taxonomy of categories and grouping of concepts into integration design. The new design process is tested and versified with an empirical review of Industry 4.0 frameworks and results with a new 5 levels reference architecture step by step model for the integration of these related systems and technologies (Industrial Internet of Things, Cyber Physical Systems, and Industry 4.0). We review 118 academic and industry papers published between 2010 and 2019. Then, we report the results of a qualitative empirical study that correlates academic literature with 14 world leading Industry 4.0 frameworks and initiatives. We therefore propose an architectural model that offers a better understanding of the systems integration between the Industrial Internet of Things and Industry 4.0.