Afterwards Armbrüster worked for a business consulting company,[2] until he, in 1999, earned his Ph.D. from the London School of Economics and Political Science.
[1][4] From 2005 to 2008 Armbrüster held the professorial chair for generic economy at the Witten Institute for family businesses at the Witten/Herdecke University.
2008 until 2009 he was president and executive director at the German Graduate School of Management and Law in Heilbronn.
[1] Since 2006 he is Adjunct Faculty in the department of Organizational Behavior and Leadership at the Mannheim Business School.
[7] In early 2006 until the end of 2014 he held the chair for strategic management at the political science faculty at the University of Erfurt.