[2][3] Haussmann worked in family business in Baden-Württemberg until 1979 when he became a member of the Bundestag in 1976 with the Free Democratic Party (FDP).

[3] On 9 December 1988, he was appointed economy minister, replacing Martin Bangemann in the post.

[4] Haussmann served in the coalition cabinet led by Helmut Kohl during the reunification process of West and East Germany.

[4] He resigned from his ministerial post on 4 December 1990, but remained in office until 18 January 1991 and Jürgen W. Möllemann succeeded him as economy minister.

[2] In 2001, he was made chairman of the advisory board of GEMINI Executive Search.