I’ve been there, staring at a blank page, trying to figure out how users will use your software. As a developer, architect, and part-time product manager, I’ve written my fair share of use cases, and let me tell you, it’s not always easy to get them right. 😵‍💫

Let me guide you through identifying and documenting use cases that make sense. Think of a use case as the story of how someone uses your software to solve a real problem. It’s not an individual feature or capability - it’s the complete picture of what users are trying to achieve.

Would you like to understand how these pieces fit together? Check out my post on the differences between these concepts.

What Makes a Well-Defined Use Case?

Here are the key characteristics of a well-defined use case:

  1. It’s All About the User - Focus on what they want to achieve.
  2. It’s Specific - Tell a concrete story.
  3. It Has Clear Boundaries - Know What’s In and Out of Scope.
  4. It’s Measurable - You can tell when it works.

How to Write Use Cases: Step-by-Step Guide

1. Start with User Goals

I begin by asking three questions:

  • What are users trying to achieve?
  • Why do they need this?
  • What problems are they solving?

2. Use My Use Case Template

Here’s a template that can help you define use cases:

Title: [Clear, action-oriented name]
Actor: [Who is using the system]
Goal: [What they want to achieve, why they need this]
Preconditions: [What must be true before this can happen]
Steps:
1. [First step]
2. [Second step]
Postconditions: [What should be true after]

3. Validate and Refine

Before you’re done, make sure to:

  • Check if it’s complete
  • Verify it’s user-focused
  • Make sure it’s testable

Real-World Example: Project Management System

Let me show you a real use case I worked on for a project management tool:

Title: Create a New Project
Actor: Project Manager
Goal: Set up a new project with basic information
Preconditions: User is logged in and has project creation permissions
Steps:
1. Click the "New Project" button
2. Enter project name
3. Select project template
4. Set start date
5. Add team members
6. Click "Create Project."
Postconditions: The Project is created and visible in the project list

Common Pitfalls and How to Avoid Them

Here are the mistakes I’ve made (so you don’t have to):

  1. Mixing Up Use Cases with Features

  2. Being Too Vague

    • “User can manage projects” is too broad
    • “Project manager creates a new project” is specific
    • “Project manager creates a new project with a template” is even better

  3. Missing Edge Cases

    • What happens if the user cancels?
    • What if required fields are missing?
    • What if the system is unavailable?

Best Practices I’ve Learned

  1. Put Users First

    • What are they trying to achieve?
    • Why do they need this?
    • Focus on user value

  2. Keep It Simple

    • One use case = one goal
    • Break complex use cases into smaller ones
    • Maintain clear flow

  3. Get User Feedback

    • Do these match real user needs?
    • Are we missing important scenarios?
    • Get feedback early

Advanced Tips

Want to take your use cases to the next level? Here’s what I’ve learned:

  1. Map Your Use Cases

    • Create a use case diagram
    • Show how use cases connect
    • Spot gaps and overlaps

  2. Prioritize Smartly

    • Rank by user value
    • Consider level of effort
    • Balance user needs

  3. Test Thoroughly

    • Create test scenarios
    • Verify user flows
    • Validate outcomes

Conclusion

Writing use cases can be fun and serving users is rewarding. As long as you focus on what users actually need and document it clearly, you’ll be good.

For more on related concepts, check out my posts on: