Preliminary results of a systematic review on requirements evolution

Background: Software systems must evolve in order to adapt in a timely fashion to the rapid changes of stakeholder needs, technologies, business environment and society regulations. Numerous studies have shown that cost, schedule or defect density of a software project may escalate as the requirements evolve. Requirements evolution management has become one important topic in requirements engineering research. Aim: To depict a holistic state-of-the-art of requirement evolution management. Method: We undertook a systematic review on requirements evolution management. Results: 125 relevant studies were identified and reviewed. This paper reports the preliminary results from this review: (1) the terminology and definition of requirements evolution; (2) fourteen key activities in requirements evolution management; (3) twenty-eight metrics of requirements evolution for three measurement goals. Conclusions: Requirements evolution is a process of continuous change of requirements in a certain direction. Most existing studies focus on how to deal with evolution after it happens. In the future, more research attention on exploring the evolution laws and predicting evolution is encouraged.