Restructuring requirements specifications

Abstract

This paper describes the restructuring of multi-perspective requirements specifications to facilitate the identification and analysis of inconsistencies and the management of change. A partial, heterogeneous and reasonably large requirements specification from a NASA project is analysed and decomposed into a structure of viewpoints, where each viewpoint encapsulates partial requirements of some system components described in the specification. Relationships between viewpoints are identified and include, not only the interactions explicitly stated in the requirements, but also some implicit and potentially problematic inter-dependencies. The restructuring process and a first informal analysis of the resulting relationships enable the detection of inconsistencies and the definition of some interesting domain-dependent consistency rules. It is believed that this restructuring into viewpoints also facilitates requirements understanding through partitioning, and requirements maintenance and evolution through explicit identification of the inter-viewpoint relationships.