use-case-modeling

What problem does it solve?

It eliminates ambiguity between stakeholder goals and implementation by converting actor-centered goals into precisely specified, testable behavioral contracts with clear preconditions, triggers, alternate paths, and durable postconditions.

Core Features & Use Cases

• Fully-dressed use case specification: Define an actor-goal interaction with explicit scope, preconditions, trigger, main path, alternate paths, failure paths, and postconditions.
• Durable, testable postconditions: Express outcomes as system state changes, emitted events, or externally observable side effects rather than UI text.
• Traceability through business-rule linkage: Require named business rules referenced by ID so designs and tests can be verified against authoritative rules.
• Risk-aware modeling: Model external systems as actors with trust-boundary preconditions and failure handling, including idempotency and state preservation.

Example use case: a billing workflow where a customer subscribes successfully through the main path but also needs explicit modeling for webhook duplicates, coupon validation failures, and payment timeouts to ensure acceptance criteria and recovery behavior are unambiguous.

Quick Start

Use this skill to model a complete, actor-goal use case for your change by describing the primary actor, their goal, the entry preconditions, the trigger, and what durable system state or events must exist when the use case succeeds or fails.