In 1995, Markus Siegers began working as a plant operator for what is now ElringKlinger AG, where he has been a member of the Works Council since 1998. From 2000 he worked as technical consultant in the Materials Simulation services of the R&D department. In 2005 he was released from his operational duties and was elected Deputy Chairman of the Works Council in 2006. At the same time, he was also appointed to the Supervisory Board of ElringKlinger AG. Since 2008, Markus Siegers has been Works Council Chairman of the Dettingen plant and General Works Council Chairman of ElringKlinger AG. Since May 2010, Markus Siegers has been deputy Chairman of the Supervisory board.