Use Case Documentation Skill

Purpose

Describe how a user interactions with a system to achieve a specific goal. Use cases capture functional requirements from a user-centric perspective, often used in Waterfall or Hybrid environments where detailed specification is needed before implementation.

When to Use

• Complex transactional systems (banking, healthcare).
• When specific alternate flows and error handling must be rigorously defined.
• Regulatory compliance requires detailed documentation.
• Bridging gap between business needs and technical functional specs.

Anatomy of a Use Case

Key Elements

1. Use Case Name: Verb-Noun phrase (e.g., "Withdraw Cash").
2. ID: Unique identifier (e.g., UC-ATM-01).
3. Actor(s): Who interacts? (Primary: Initiates; Secondary: External systems).
4. Description: Brief summary of goal.
5. Preconditions: What must be true BEFORE this starts? (e.g., "User is logged in").