He worked for GTE Automatic Electric and Bell Laboratories before joining the University of Illinois at Chicago in 1984, where he directed the International Center for Software Engineering.

He served as Professor and Director for the Institute for Mobile, Pervasive, and Agile Computing Technologies (IMPACT) at Auburn University from 2001 to 2002, before moving to Iowa State University in July 2002 to take the department chair position.

[3] As a three times winner of IBM Faculty Award, Chang's research interests include software engineering, human computer interaction and digital health.

He is the founder of Situation Analytics[15] based on his Situ theoretical framework.

[11] He is the recipient of the 2014 Overseas Outstanding Contribution Award[4] from China Computer Federation (CCF 中国计算机学会) as well as the 2014 Distinguished Alumnus by the National Central University in Taiwan (中央大學－台灣)。