Feature-oriented Requirements Satisfy Needs for Reuse and Systems View

Requirements engineering at the Swiss hearing aid maker Phonak brings multiple challenges, including (a) fast product cycles, creating a need for requirements reuse; (b) complex hardware-software systems, consisting of hearing instrument hardware, embedded software and PC-based software; (c) an organization composed of roles responsible for individual products or components rather than systems. We chose to segment requirements by feature, with each feature described in a separate, independently reviewed document, which typically contains multiple use cases, business rules and nonfunctional requirements. Feature requirements specifications are versioned, and a specific version is referenced by product- specific requirements documents, thereby fulfilling the need for reuse of requirements across product families. The feature requirements specification describes the behavior of all affected products, fulfilling the need for a system-level view.