Digitisation and smart technologies, according to prominent researchers, are radically affecting economies, industries and societies all over the world. The digital transformation, of the fourth industrial revolution, dubbed the “second wave” in Industry 4.0 (Kagermann et al., 2018). Digitisation is recognised as the basis for cyber-physical manufacturing systems. Digitisation (i.e. the process of transforming analogue data into digital data sets), combined with technologies attributed to the concept of Industry 4.0 (cloud computing, smart sensors, big data, 3D printing, artificial intelligence to support machine learning, computer-based vertical and horizontal business integration systems, virtual and augmented reality solutions), has opened up new opportunities to bring about changes in processes within companies and across supply chains. Chapter two outlines the impact of digital and smart changes on the steel industry. However, the steel industry's transformation to smart steel manufacturing will require consideration of the requirements of global climate policy (Strategy 2050 “Net Zero”). The global steel industry generates about 7% of global greenhouse gas emissions. To meet its emission targets, the steel industry will need to be climate-neutral by the end of 2050. The deep decarbonisation of the steel industry will result in the replacement of existing high-carbon technologies with low carbon and, in the future, zero-carbon, or green steel.