| 1974–1975: | Technical engineer at an industrial laundry and dry cleaning company in Dresden/Germany |
| 1976: | Technical engineer for research and development at Siemens AG/Austria |
| 1976–1984: | Systems analyst at the Computer Center of the University of Vienna Medical School at the Department of Medical Computer Sciences/Austria |
| 1986–1992: | Senior Research Associate at the Department of Medical Computer Sciences, University of Vienna/Austria |
| 1987: | Foundation and project leader of the "Medical Expert Systems Laboratory" at the Department of Medical Computer Sciences, University of Vienna/Austria |
| 1988: | "Habilitation zum Universitätsdozent" (university lectureship) in Medical Informatics at the University of Vienna Medical School/Austria |
| January 1990: | GDMS/GI certificate "Medical Computer Scientist" according to the guidelines of the German Society for Medical Documentation, Informatics, and Statistics (GDMS) and the Society for Informatics (GI) |
| 1992: | "Außerordentlicher Titular Universitätsprofessor" (Berufstitel) (Associate Professor) at the Department of Medical Computer Sciences, University of Vienna/Austria |
| 1992: | Extension of the "Medical Expert Systems Laboratory" to "Section on Medical Expert and Knowledge-Based Systems" at the Department of Medical Computer Sciences, University of Vienna/Austria |
| 1997: | "Außerordentlicher Universitätsprofessor" (Amtstitel) (Associate Professor) at the Department of Medical Computer Sciences, University of Vienna/Austria |
| 10/3/2001–9/30/2015: | Head of the Section on Medical Expert and Knowledge-Based Systems of the Department of Medical Computer Sciences at the University of Vienna, now: Section for Medical Expert and Knowledge-Based Systems of the Center for Medical Statistics, Informatics, and Intelligent Systems at the Medical University of Vienna/Austria |
| 2/4/2002–12/31/2005: | Foundation and Director of the Ludwig Boltzmann Institute for Expert Systems and Quality Management in Medicine, Vienna/Austria |
| since 8/27/2002: | Foundation, CEO, and Scientific Head of Medexter Healthcare GmbH (university spin-off) |
| 1973: | Medical image processing project during a three-months practical training at the Department of Pathology, Medical Academy of Dresden (now: Medical School of the Technical University of Dresden/Germany) |
| 1975–1976: | Research associate at the Austrian Academy of Science "Man and Biosphere High Mountain Program" |
| 1983: | Participation in a three-months "Young Scientists' Summer Program" at the International Institute for Applied Systems Analysis, Laxenburg/Austria |
| 1984–1986: | Visiting Research Fellow at the Computer Science Division, Department of Electrical Engineering and Computer Science, University of California, Berkeley/U.S.A.; Fellowship of the Max-Kade-Foundation/New York |
| 6/1–8/31/1993: | Visiting Associate Professor at the Department of Medicine, Section on Medical Informatics, Stanford University School of Medicine, Stanford/U.S.A.; Fulbright-Fellowship |
| 7/1–8/5/2000: | Visiting Scholar at the Department of Electrical Engineering and Computer Sciences, Computer Science Division, Berkeley Initiative in Soft Computing (BISC), University of California, Berkeley/U.S.A. |
| 11/1/2002–9/30/2015: | Head of MES Program of the Memorandum of Understanding for the Establishment of a Research Link between Berkeley Initiative in Soft Computing (BISC) Program, Electrical Engineering and Computer Sciences Department at the University of California, Berkeley, U.S.A. and Section of Medical Expert and Knowledge-Based Systems (MES), Department of Medical Computer Sciences at the University of Vienna Medical School, Vienna/Austria |
| 5/1–5/31/2005: | Visiting Research Fellow at the Department of Computer Science, Meiji University, Kawasaki/Japan |
| 9/1–9/30/2008: | Visiting Scientist at the Clinical Decision Making Group, Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology (MIT), Cambridge, U.S.A. |
| 1979–2003: | Teaching position at the University of Vienna Medical School (various classes on different subjects of Medical Informatics) |
| 1982–1993: | Teaching position at the Vienna University of Technology (classes on Medical Expert Systems) |
| 1995–1997: | Teaching position at the Technical University Graz/Austria (classes on Expert Systems in Medicine) |
| spring 1998–2001: | Guest Professor at the Technical University Graz/Austria (classes on Expert Systems in Medicine) |
| spring 2002–2004: | Teaching position at the Technical University Graz/Austria (classes on Expert Systems in Medicine) |
| since 2004: | Teaching position at the Medical University of Vienna (classes on Clinical Decision Support and Artificial Intelligence in Medicine) |
| 2006–2016: | Teaching position at the University of Vienna (classes on Medical Informatics) |