Laser processing is currently highly dependent on user knowledge and experience to choose correct parameters to obtain a reliable and high quality joints. Alternatively for every new application or different laser system a new process development is required. This is the reason that laser processing is often called as ‘black art’ which limits the exploitation of laser based production process in industry. The development of the Expert Laser System (ELS) for keyhole CW laser welding greatly simplifies the selection of laser welding parameters.