A framework for software problem analysis

The paper introduces a software problem calculus based on a viewof requirements engineering proposed by Zave and Jackson, that wehope can underpin techniques and processes in requirements engi-neering and early software design. The approach is centred aroundthe notion of problem and problem transformation. It is proposi-tional in nature in that it allows for heterogeneous problem descrip-tions and correctness argumentation for the validation and verifica-tion of solutions. We present a number of fundamental rules topopulate the calculus including ‘divide-and-conquer’ problem de-composition, description reification, prior-solution reuse, the use ofarchitectures for solution structuring. In addition, and central to thefoundational nature of the calculus is the interpretation and subse-quent incorporation into our framework of others’ work as problemtransformations. This is an on-going task: examples presented inthis paper include interpretations of simple goal-oriented decompo-sitions and viewpoints. The calculus also provides rich traceabilityof the requirements of an original problem through transformationto those of its solution. We use the design of a sluice gate as asimple running example throughout the paper.