Bridging User Story Sets with the Use Case Model

User Stories (US) are mostly used as basis for representing requirements in agile development. Written in a direct manner, US fail in producing a visual representation of the main system-to-be functions. A Use-Case Diagram (UCD), on the other hand, intends to provide such a view. Approaches that map US sets to a UCD have been proposed; they however consider every US as a Use Case (UC). Nevertheless, a valid UC should not be an atomic task or a sub-process but enclose an entire scenario of the system use instead. A unified model of US templates to tag US sets was previously build. Within functional elements, it notably distinguishes granularity levels. In this paper, we propose to transform specific elements of a US set into a UCD using the granularity information obtained through tagging. In practice, such a transformation involves continuous round-tripping between the US and UC views; a CASE-tool supports this.