Agile software development methodologies are driven by user created stories known as scenarios. These scenarios capture a subset of the program's functionality and often permit developers to perform an ad hoc form of program slicing. We developed a tool, and integrated it into Microsoft Visual Studio 2005, to formalise the slicing of a program based on a specified scenario. During development, programmers are required to insert, using a predefined macro, an XML tag set before all methods and class variables that they add, edit, or reference. Our slicing tool uses these tags to identify the methods and variables associated with a specific scenario and to create a compilable program slice that implements only the scenario. Scenario-based slices can be used by both developers and managers in support of tasks that include, but are not limited to, debugging, metric generation (e.g., complexity), cost estimation, prioritization, and requirements tracing.