To develop a technique and a tool to ease change management in telephony, by detecting and eliminating feature interaction (undesirable interference of new features with existing ones) is the goal of this paper.

The problem is clearly introduced in the introduction. The features, when realized, constitute a concrete layer. The functionality requirements are in an abstract layer. The authors’ approach allows users to formulate and update requirements incrementally. The hierarchical approach shields the abstract requirements from the concrete details of system implementation, by at least one intermediate level of abstract logical concept, defined as a condition on the system state. In this component-based approach, the telephone system is modeled as a set of component processes, and linear-time temporal logic is used. Each component process is modeled as an automaton, and these automatons communicate with each other, and with their environment, by broadcasting events.

In an example discussed in detail in the text, the initial base system, and initial features, are respectively described by ten and 15 requirements. In their conclusion, the authors compare their results with the report of a contest. According to the authors, their tool was used to detect and solve three interactions, and eight interactions were detected but not solved. The authors refer to related works, and provide an adequate bibliographic list of references.

In the challenging area of change management for evolutionary systems, it would be highly desirable to develop specification schemas and tools that allow requirements to be managed even more easily.