Seven Years of XP - 50 Customers, 100 Projects and 500 Programmers - Lessons Learnt and Ideas for Improvement

Over the last seven years we have been using eXtreme Programming (XP) in two commercial software development settings within the University of Sheffield. The detailed performance of a variety of different project teams has been analysed by the Sheffield Software Engineering Observatory - a joint research project between the Department of Computer Science and the Institute of Work Psychology - during this period, based on empirical data collected from these projects. A number of research questions have been investigated: the comparison between XP and a traditional software development approach in terms of product quality and the impact on quality of the number of XP practices used etc. Problems associated with some aspects of XP have been identified and adaptations and development of the XP methodology have been introduced. Other issues studied in the Observatory include the relationship between methodology and individual well being; the impact of personality on project outcomes; the level of conflict in different groups; the relationships between customers and programmers and issues relating to testing. The possible benefits of XP have been assessed alongside the problems with implementing the methodology in a variety of settings. ’People’ issues are a major determinant in successfully adopting the XP approach in a sustainable way. This paper is a brief review of some of this work.