He is a founder of the International Workshop on Planning and Scheduling for Space held every other year from 1997 onward and was the Chair or Co-chair of numerous workshops. He is former chair of the AIPS Executive Council (2000-2002), was a founding member of the ICAPS Executive Council (2002-2006), and was founding President of the ICAPS Executive Council 2002-2004. He was also a Councilor for the American Association for Artificial Intelligence (2003-2006)

Dr. Chien was a recipient of the 1995 Lew Allen Award for Excellence, JPLs highest award recognizing outstanding technical achievements by JPL personnel in the early years of their careers. In 1997, he received the NASA Exceptional Achievement Medal for his work in research and development of planning and scheduling systems for NASA. He is the Team Lead for the ASPEN Planning System , which received Honorable Mention in the 1999 Software of the Year Competition and was a contributor to the Remote Agent System which was a co-winner in the same 1999 competition. In 2000, he received the NASA Exceptional Service Medal for service and leadership in research and deployment of planning and scheduling systems for NASA. He is the Principal Investigator for the Autonomous Sciencecraft Experiment which is a co-winner of the 2005 NASA Software of the Year Award. In 2007, he received the NASA Exceptional Achievement Medal for outstanding technical accomplishments in the development of the Autonomous Sciencecraft deployed on the Earth Observing One Mission and the development of the Earth Observing Sensorweb. In 2011 He was awarded the innaugural AIAA Intelligent Systems Award, for his contributions to Spacecraft Autonomy. In 2011, he was the team co-lead for the Sensorweb Toolbox team, which was awarded Honorable mention in the 2011 NASA Software of the Year Competition. In 2015 He was awarded a JPL Magellan Award as well as the NASA Exceptional Achievement Medal for his contributions to automated science scheduling for ESA's Rosetta mission.