Their Successors were Christian Wachter , Tobias Blickle and Rudolf Keul .
In June , 2014 , Wolfgang Kraemer , Frank Milius , and Volker Zimmermann , founding Board members , left the company after 17 years .
Board members ' Successors were Christian Wachter , Tobias Blickle and Rudolf Keul .
In June , 2014 , Wolfgang Kraemer , Frank Milius , and Volker Zimmermann , founding Board members , left the company after 17 years .