Impacts are the key aspects in software engineering when it identified earlier can reduce the overhead in all the phases of development. Although the existing works are addressed on change impact analysis over software development phases. We believe that analyst experience during requirement elicitation can provide way to identify the impact based requirements. In this paper author discuss a new process for impact analysis over requirements. We address how informal requirements of the system under impact analysis to evolve and represented using different models like transition and sequence. The proposed approach is based on the impact-transition structure that was elicit impact oriented requirements and its analysis. This work illustrated through a case study to realize the proposed approach with precision, recall and F-measure. © 2019 Mattingley Publishing. All rights reserved.