The Internet of Things (IoT) is captivating the society because of its potential to rapidly transform businesses and people's lives. It is widely believed that IoT will also transform the industrial automation business in terms of improved productivity, less cost, flexibility, and increased revenues. Hence, there are some challenges that needs to be addressed when IoT is introduced to the industrial automation domain. This paper aims to present realistic requirements and highlights identified challenges such as security, interoperability, deterministic and low latency communication, and how the required availability (uptime) can be kept. Moreover, the paper also point out the need of standardization and sustainable business models. The conclusion is that introducing IoT devices and connecting them directly to cloud services is not straightforward for process automation.