Modification analysis is an essential phase of most software maintenance processes, requiring decision makers to perform and predict potential change impacts, feasibility and costs associated with a potential modification request. The majority of existing techniques and tools supporting modification analysis focusing on source code level analysis and require an understanding of the system and its implementation. In this research, we present a novel approach to support the identification of potential modification and retesting efforts associated with a modification request, without the need for analyzing or understanding the system source code. We combine Use Case Maps with Formal Concept Analysis to provide a unique modification analysis framework that can assist decision makers during modification analysis at the requirements level. We demonstrate the applicability of our approach on a telephony system case study.