IoT, digital twins, co-bots, drones, Artificial Intelligence, clouds are the system components of Industry 4.0, this trend born to face hypercompetition. It aims in renewing processes using available technologies and impacts the whole industry ecosystems including people, information processing and business models. While most of research works focus on technology, the industrial systems objectives are economic with recent environmental concern. This paper provides an overview of Industry 4.0 and discuss the importance of considering knowledge, people and planet in massive digitalization. It focus on the role of digital twins in transforming industry, presented in the context of ecosystems and discuss the role of Knowledge Innovation, environmental impact and the place of the humans in I4.0.