Integrated structured analysis and formal specification techniques

Abstract

The last decade has seen a large increase in the use of 'structured' methods of software development. They grew out of their predecessors, which consisted of a toolkit of techniques with little method of how and when to apply them. Methods such as Yourdon Structured Analysis1 and SSADM2 provide means of managing the complexity of large systems. They provide techniques and associated procedures for the development of such systems. In parallel with this, and almost entirely independently, formal specification languages and methods have been developed. Both approaches have their strengths and weaknesses. Recently it has been recognised that benefits can be gained from integrating the two.A number of researchers have reported progress towards the successful integration of formal and structured methods. This paper reports on a selection of this work. The aim in each case has been to develop specifications which are both structured and formal, and so combine the proven advantages of both approaches. We believe that such integrated methods remove some of the 'culture shock' associated with the introduction of mathematically formal languages, and make their use more acceptable to managers and engineers in software development organisations. There is some evidence for the feasibility and cost-effectiveness of this approach when used in an industrial setting; developers at Rolls Royce Associates3 have reported the successful combined use of VDM and Yourdon.Work has also started on the integration of formal notations and graphical techniques for Object-Oriented Analysis and Design, but this is all at a very early stage and little has been reported formally. © 1992 The British Computer Society.