Most books about specifications still assume that requirements can be known up front and won't change much during your project. In today's βreal world,β however, you must specify and build software in the face of high and continuing uncertainty. Scrum and other agile methods have evolved to reflect this reality. Now, there's a complete guide to specifying software in agile environments when prerequisites are unclear, requirements are difficult to grasp, and anything about your project could change. Long-time agile coach and enterprise architect Mario Cardinal shows how to create executable specifications and use them to test software behavior against requirements. Cardinal shows how to trawl requirements incrementally, step-by-step, using a vision-centric and emergent iterative practice that is designed for agility. Writing for analysts, architects, developers, and managers, Cardinal makes a strong case for the iterative discovery of requirements. Then, he moves from theory to practice, fully explaining the technical mechanisms and empirical techniques you need to gain full value from executable specifications.