A framework for reasoning about requirements evolution

Abstract

We present a logical framework for modelling and reasoning about requirements evolution in the construction of information systems. Our framework represents a requirements model as a theory of some nonmonotonic logic, while requirements evolution is modelled as a mapping between such theories, based on the AGM logic of belief change [1]. We demonstrate our ideas by using the THEORIST system for nonmonotonic reasoning. Moreover we examine the Telos system for requirements modelling in terms of our framework, and we identify some obvious shortcomings and propose possible solutions. We argue that our framework provides a powerful tool both for analysing and comparing existing systems and for developing automated systems to support requirements evolution.