Su’s primary research interests are in data modeling and access languages, data management, web services, formal verification, modeling of processes with data, and management of business processes. He has studied/is studying data manipulation languages for relational databases, complex objects or nested relations, and object-oriented databases; incremental query evaluation and view maintenance; database models for spatial and scientific databases; complexity and expressive power of constraint query languages; automata-based verification techniques for software systems; web service modeling, composition, and verification; choreography for collaborative processes; formal models for business processes based on business artifacts; workflow system applications in government agencies, in healthcare, and in businesses. His current focus is on data modeling and management for workflow, data-centric workflow modeling, web services, BPM.