Nowadays the modeling development process suffers from being an effort to meet project deadlines. Typically, the architecture effort is separated from the Systems Engineering (SE) leading to a lack of traceability from the system requirements and design to the architecture. An Industrial Internet of Things (IIoT) system connects and integrates systems and software engineering with enterprise systems, business processes, and analytics, which supports decision makers. Though it sounds promising, there are very limited formal techniques to define IIoT architectures. In this paper, an emerging international standard called the Unified Architecture Framework (UAF), its potential application to capture IIoT architectures, its ability to help the systems integrator to develop interoperable systems, with traceability to requirements and across different viewpoints, is analyzed. A mapping of the Industrial Internet Reference Architecture (IIRA) to UAF is described and a real-world case study is provided to show the application of the UAF to modeling IIoT architectures.