ABSTRACT. Existing systems analysis and requirements capture are mostly temporally myopic: they only consider current requirements and concerns, and they do not draw upon the wealth of experiences surrounding the adoption of previous systems. This paper presents a tool, Temporal Stakeholder and Event Analysis (TSEA), to help IS/IT developers explore with stakeholders, likely evolving system changes. TSEA builds on heedful interaction and past experience of stakeholders to help organisations evaluate new systems. The result is a roadmap of likely evolving system requirements and corresponding impact on stakeholder groups. The paper is informed with theory, literature and previous research involving two diverse case studies. The paper contributes to practice showing how system requirements evolve, and contributes to theory by developing a richer temporal view of IS/IT development and diffusion.