Requirements engineering is an important component of effective software engineering, yet more research is needed to demonstrate the benefits to development organizations. While the existing literature suggests that effective requirements engineering can lead to improved productivity, quality, and risk management, there is little evidence to support this. We present empirical evidence showing how requirements engineering practice relates to these claims. This evidence was collected over the course of a 30-month case study of a large software development project undergoing requirements process improvement. Our findings add to the scarce evidence on RE payoffs and, more importantly, represent an in-depth explanation of the role of requirements engineering processes in contributing to these benefits. In particular, the results of our case study show that an effective requirements process at the beginning of the project had positive outcomes throughout the project lifecycle, improving the efficacy of other project processes, ultimately leading to improvements in project negotiation, project planning, and managing feature creep, testing, defects, rework, and product quality. Finally, we consider the role collaboration had in producing the effects we observed and the implications of this work to both research and practice

There is limited evidence (Brooks (1987), Fosberg and Mooz (2000) and S. Robertson and J. Robertson (1999)) which supports claims in literature that requirements engineering (RE) can have positive effects on an organization's ability to manage project risk. Such evidence can serve to motivate industrial adoption of requirements engineering techniques, but it can also contribute to our understanding of the role of RE in supporting project management activities. This paper presents an analysis of the causal relationship between RE practice and benefits in risk management in one software organization that revised its RE process and enjoyed improvements in its project management activities. In particular, we present insights from our investigation of the interaction between the RE process and the processes of project planning and SQA. We found that elements of the RE process such as feature decomposition, structure documentation and traceability links improved feature sizing and enabled effective change management, contributing to improved risk management activities. These findings are useful to practitioners in similar software organizations whose product release objectives originate from a remote business unit and who currently suffer from significant feature creep.