On the Reliability of Industrial Internet of Things from Systematic Perspectives: Evaluation Approaches, Challenges, and Open Issues.

In the light of Industry 4.0 revolution, the Industrial Internet of Things (IIoT) allows digitalizing manufacturing processes and increasing the digital connectivity and automation in the smart factories and industrial systems. The reliability of a system is considered as a key performance indicator that defines how accurately and perfectly the system works. Ensuring reliability in the IIoT systems presents several challenges due to the presence of uncertain and dynamics in the industry environment as well as the complex nature of industrial systems. While there are no standard frameworks proposed and applied for the IIoT systems with multiple reliability levels, the challenges reveal many promising opportunities for the research and practical implementation including advancing technologies and systematic designs such as algorithms, architectures, and devices. However, there are a few works studying the reliability-related aspects of the industrial systems in the existing literature, they lack a framework to conduct the study and examination of reliability of IIoT systems in a holistic manner. In this regard, this article will elucidate and survey several performance-improvement methods and techniques for better reliability and further challenges to be overcome for highly reliable IIoT systems. Finally, by defining several open research issues, we expect to draw more attention for both the academic researchers and practitioners toward designing and developing reliable solutions and frameworks. [ABSTRACT FROM AUTHOR]