Transferring success in managing requirements change: patterns of achievement

The problem of reengineering information technology systems in response to rapidly changing business process requirements is generally recognised as one of the most significant challenges facing both managers and software engineers. This is due to the size and complexity of such systems, many of which, including those being produced today, were never designed for ease of modification. These factors mean that modifications are extremely difficult to achieve in a timely and error free manner. We introduce the idea of software reengineering patterns, which adapt ideas from design patterns to identify successful reengineering projects and to make the lessons from them available to new projects. The ideas are developed in terms of some tentative examples taken from real projects. Our aim is to understand the way in which experienced software practitioners undertake the successful reengineering of legacy systems, so that we can develop better techniques and material for transferring expertise. Specifically, we aim: to identify a collection of important, validated reengineering patterns; and to establish that the pattern paradigm is useful in reengineering. We do not expect to develop a comprehensive pattern language immediately. However, we have begun to identify and disseminate the idea and some candidate patterns. In addressing audiences like this, we believe that the urgency of the problem and the nature of the software engineering community will carry the work of identifying reengineering patterns beyond our immediate project, with escalating benefits