Visualizing the effects of requirements evolution.

Changes to software requirements occur throughout the software life cycle. Requirements engineers who maintain software systems in regulated environments must identify the affected artifacts when requirements change. This identification is critical to: (a) ensure continued compliance with regulations, and (b) accurately estimate budget requests. Previously, we introduced Requirements Evolution Charts (REC) to provide a visual representation of requirements evolution history. An REC is generated from the issue tickets in which requirements engineers record changes to requirements artifacts. Herein, we examine whether a REC helps software engineers conduct an impact analysis. Thirty experienced NTT requirements engineers with no prior domain knowledge identified the impact of seven requirements changes in a large-scale system governed by Japanese laws and regulations. They were divided into two groups of fifteen engineers. The REC group employed the REC to aid their efforts; the Non-REC group conducted their impact analysis without the REC. Participants in both groups identified which of the 139 artifacts were affected based on a history of 108 issue tickets. Our study reveals that engineers in the REC group identified the affected artifacts more accurately and quickly than the Non-REC group, suggesting that the REC is a valuable tool for examining the impact of requirements evolution.