Abstract :
The ideas behind the use of modern structured systems development methodologies are examined, and the author highlights the main changes that have taken place within these methodologies during recent years. He then explores an alternative paradigm, that of evolutionary systems development, and attempts to illustrate that the previously mentioned changes in structured systems methodologies can be seen as supporting, and perhaps even heralding, a paradigm-shift to evolutionary development. He begins by examining briefly the nature of systems development methodologies, and discusses the reasons for the wide variety of occurrences. Starting with an overview of the major structured analysis and design methods promulgated at the beginning of the 1980s, the author goes on to illustrate how new ideas have been incorporated to extend and strengthen these approaches, and comments are made on the directions in which these changes have moved the various methodologies. The evolutionary paradigm is then explained, and a comparison is made with the ideas behind the methodologies just described, to illustrate the implications of the differences
