- Workshop on Prognosis PHM approaches for Complex Engineering Systems (PACES), College Park, MD, 2020. (Co-organizer along with K. Groth)
- International Topical Meeting on Probabilistic Safety Assessment (PSA 2019), Charleston, SC, April 28-May 3, 2019 (Technical Program Chair). (300 participants).
- Workshop on Risk Analysis for Autonomous Vehicles: Issues and Future Directions, College Park, MD, April 26, 2019, Over 50 participants.
- 25th Reliability Engineering Anniversary Symposium: Promise of a Discipline: Reliability and Risk in Theory and Practice, College Park, MD, April 2, 2014.
- Nuclear Safety Workshop, (Organized for Department of Energy), Rockville, MD September 2012.
- Societal Safety Goal Workshop, Organized for the Institute of Nuclear Energy Science and Technology (INEST) of the Idaho National Laboratory, College Park, MD, March 2012.
- Small Modular Reactor Symposium University of Maryland Energy Research Center, April 29, 2011.
- Integrated Uncertainty Analysis, (Organized with A. Mosleh) for the U.S. Nuclear Regulatory Commission), May 19-20, 2009, Annapolis, MD.
- International Workshop on Software & System Engineering (IWSSE), Istanbul, Turkey, September 5-9, 2004 (General Chair).
- 2nd Workshop on Use of Risk Information in Government, Inn and Conference Center, College Park, MD, Dec. 10-12, 2003.
- 10th International Conference On Nuclear Engineering (ICONE-10) Arlington, VA, April 14-18, 2002 (Technical Program Chair for the Risk and Reliability track). (Over 800 participants).
- 6th International Functional Modeling Workshop, College Park, MD, August 23 – 24, 2002.
- Use of Risk Information by Agencies of the Federal Government, College Park, March 6-7, 2001.
- 2000 American Nuclear Society/European Nuclear Society Meeting, Washington, D.C., November 12 – 17, 2000 (Technical Program Chair) (Over 1200 participants)
- 8th International Conference On Nuclear Engineering (ICONE-8) “Nuclear Energy in the new Millennium” Baltimore, MD, April 2-6, 2000 (Technical Program Chair for the Risk and Reliability track). (Over 800 participants)
- International Topical Meeting on Probabilistic Safety Assessment (PSA’99), Washington, DC, August 22-26, 1999 (Technical Program Chair). (Over 400 participants)
- 5th International Functional Modeling Workshop, Paris, France, July 1 – 3, 1997.
- 4th International Functional Modeling Workshop, Athens, Greece, June 20 – 21, 1996.
- 3rd International Functional Modeling Workshop, Washington, D.C., June 30 – July 1, 1995.
- ANS Topical Meeting on Computer-Based Human Support Systems: Technology, Methods and Future, Philadelphia, PA, 25-29 June 1995.
- 2nd International Functional Modeling Workshop, Copenhagen, Denmark 13 – 15, August 1994.
- 1st International Workshop on Functional Modeling of Complex Technical Systems, Ispra, Italy, 12 -14, May 1993.
- Expert System Development, at ANS Conference on Man-Computer Interactions: Nuclear and Beyond June 10, 1990, Nashville, Tennessee