Industry 4.0 is the last phenomenon that has brought the industry to a new level of process optimisation, and one of its key elements is the Machine Learning. This thesis aims to depict the current Machine Learning methodologies and techniques present in the current industrial system, highlighting challenges and future opportunities. The study is going also to dig and further analyse the fields in which these algorithms are used the most, like the Digital Twin, a new technology that is becoming a standard in the industrial technologies.