UML activity models (activities, for short) have become widely accepted for specifying the dynamic behavior of use cases. For an adequate specification of use cases in the context of interactive systems, however, activities must be adapted in several aspects. We present a tailoring of activities to these needs yielding so-called interactionoriented activities. From such activities we derive two kinds of activities focusing on the development process. The first activity is a user-friendly variant that is devoted to the requirements engineering stage. The second activity is obtained by a smooth transformation of the first one. It is a more detailed variant serving as a software specification guiding the implementation. We demonstrate how the latter activity can systematically be mapped to a specific target platform. As an example platform we choose J2EE with Web tier based on the framework Struts. 1 Interaction-Oriented Activities In recent years, UML activity models [3] have become wid...