Many object-oriented systems, such as CASE tools manipulated by GUIs and Java Servlet applications responding to requests from internet clients, are driven by external inputs. We call such systems object-oriented effect systems. Features in an object-oriented effect system are implemented so that they can collaborate each other by effects, but sometimes defects about effects cause a kind of feature interactions, called effect interactions, specific to object-oriented effect systems.

We explain why locating the defect of effect interactions is difficult, and we explain our basic idea toward a trace analysis approach to solve the problem. We propose a model of program execution traces on which a low-level representation of effect interactions appear. We also address how to abstract the low-level representation and to express hypotheses about the location of defects of effect interactions.