Chen held several administrative appointments at the National University of Singapore (NUS).
Chen's research interests include the Stein-Chen method of Poisson approximation which deals with the probability of rare events.
This method and technique is widely applied in many areas ranging from molecular biology to computer science.
He was the first Asian to be elected president of the Bernoulli Society for Mathematical Statistics and Probability from August 1997 to July 1999, and was the first East Asian to be elected president of the Institute of Mathematical Statistics from August 2004 to July 2005.
Among his numerous local and international awards and honours are his election as Fellow of TWAS, The World Academy of Sciences in 2000 and Fellow of the Singapore National Academy of Science in 2011; a Public Administration Medal (Silver) in 2002; and the conferment by the French Government of the title of Chevalier dans l'Ordre des Palmes Académiques in 2005 for his service to education.