A Discipline for Handling Feature Interaction

A challenging problem within the wider software evolution problem is the development of systems by features. While most of the recent work centered around the detection of feature interactions, we present an approach based on modular specification, separation of concerns and prevention of unwanted interactions. We illustrate our approach extending a formalism for the specification of reactive systems and showing its application to some aspects of the well-known case of telephone systems (POTS and variations). The paper concentrates more on the methodological aspects, which are, at large extent, independent of the formalism. Indeed, this seems to be the case of some rather novel concepts like the distinction between pre-features (features in isolation) and features, closed and open semantics, feature composition and discipline of feature interaction, and finally the pervading role of a kind of anti-frame assumption.