The evolution of Web Applications needs to be supported by the availability of proper analysis and design documents. UML use case diagrams are certainly useful to identify features to evolve, as well as to study the Web Application evolution in terms of features added/removed or changed. Unfortunately, very often the only source of documentation available is constituted by the Web Application source code.

This paper proposes an approach to abstract use case diagrams from execution traces of a Web Application. The approach is mainly based on the analysis of a graph modelling the transitions between the pages navigated along user sessions and the clustering of the navigated pages. A case study carried out to validate the proposed approach and showing its feasibility is reported in the paper.