What problem does it solve? Writing use cases that stakeholders can confirm and developers can implement is hard: scenarios mix levels, branch logic clutters the main flow, and failure handling gets lost. This Skill structures use case authoring and review based on Alistair Cockburn's Writing Effective Use Cases. ## Core Features & Use Cases - Full and brief templates: Provides complete and casual use case formats with per-field guidance on what to write and what to avoid. - Level and granularity judgment: Distinguishes summary, user-goal, and subfunction levels so scenarios stay at 3-9 steps and one actor's goal. - Extension notation rules: Explains when to use step-specific (2a), ranged (2-5a), and global (*a) extensions, and how to separate extensions from technical variations. - Discovery workflow: The references include an actor-goal list method for enumerating multiple use cases before detailing them, plus a review checklist and a worked order-confirmation example. - Use Case: When asked to organize requirements for an e-commerce checkout, produce an actor-goal list first, then detail the selected use case with main success scenario, extensions, and guarantees. ## Quick Start Ask the assistant to write a use case for confirming an order in an e-commerce system, including the main success scenario and failure extensions.
