- 2023 Joerg Lichtenberg Consulting International, Haan
- 2022-2023 Zwilling Beauty Group GmbH, Düsseldorf
- 2022 WSAudiology, Lynge, Denmark
- 2021-2022 Kendaxa Group GmbH, Leipzig und Prag
- 2021 Eduard Kronenberg GmbH, Haan
- 2015-2020 Dormakaba International Holding GmbH, Ennepetal
- 2014-2015 Gardner Denver, Milwaukee
- 2007-2014 DORMA GmbH& Co. KG, Ennepetal
- 2003-2007 Schiffer Dental Care Products LLC, Longmeadow, MA, USA
- 1999-2002 Lindal GmbH, Bad Oldesloe
- 1998-1999 DORMA GmbH& Co. KG, Ennepetal
- 1993-1998 DORMA GmbH& Co. KG, Singapore
- 1991-1993 Kienbaum Executive Consultants; Düsseldorf