  Currently, Blockchain (BC), Artificial Intelligence (AI), and smart
Industrial Internet of Things (IIoT) are not only leading promising
technologies in the world, but also these technologies facilitate the current
society to develop the standard of living and make it easier for users.
However, these technologies have been applied in various domains for different
purposes. Then, these are successfully assisted in developing the desired
system, such as-smart cities, homes, manufacturers, education, and industries.
Moreover, these technologies need to consider various issues-security, privacy,
confidentiality, scalability, and application challenges in diverse fields. In
this context, with the increasing demand for these issues solutions, the
authors present a comprehensive survey on the AI approaches with BC in the
smart IIoT. Firstly, we focus on state-of-the-art overviews regarding AI, BC,
and smart IoT applications. Then, we provide the benefits of integrating these
technologies and discuss the established methods, tools, and strategies
efficiently. Most importantly, we highlight the various issues--security,
stability, scalability, and confidentiality and guide the way of addressing
strategy and methods. Furthermore, the individual and collaborative benefits of
applications have been discussed. Lastly, we are extensively concerned about
the open research challenges and potential future guidelines based on BC-based
AI approaches in the intelligent IIoT system.
