One of the most important processes in software development is clearly defining requirements. However, writing requirements can be challenging for someone with little or no experience. Studying software requirements in depth is not always practical either. In such cases, user stories become a highly useful tool. Unlike traditional software requirements documentation, user stories are written in an easy-to-understand language and structure.

In this article, we will explore what user stories are and how to write them. Additionally, we will look at how to effectively use epics and acceptance criteria.

1. What is a User Story?

A user story is a way to express software requirements in a simple and clear manner. It is commonly used in Agile development methodologies, facilitating smooth communication between developers and non-developers. A user story follows this basic structure:

User Story Template:

“As a [user], I can do [action]. (optional) So that I can achieve [value].”

This format explains the user’s goal and the benefit they expect in a concise way. For example:

“As a user, I can change my password so that I can maintain the security of my account.”

This simple format helps convey the requirements clearly, making it easy for non-experts to write and understand.

2. The Difference Between Epics and User Stories

One concept that is often confused with user stories is epics. An epic is a large requirement that is too big to be captured in a single user story. It consists of multiple user stories that can be broken down into smaller, actionable items.

For example, let’s look at an epic:

Epic: “User Account Management”

To complete this epic, several user stories would be needed. Each user story is derived from the epic and represents a small, actionable unit. For example, the epic could be divided into the following user stories:

“As a user, I can change my password.”
"As an admin, I can deactivate individual user accounts.”

The relationship between epics and user stories is hierarchical. The epic represents the big picture, and user stories break that down into more specific, actionable tasks.

3. Principles of Writing Good User Stories

To write a good user story, it’s important to follow certain principles. Here are six key principles for writing effective user stories:

1. Independent: A user story should be independent of other stories.
2. Negotiable: A user story should not be fixed; it should be flexible enough for changes.
3. Valuable: A user story should provide direct value to the customer.
4. Estimable: A user story should be able to be estimated in terms of time and resources.
5. Small: A user story should be small enough to be completed in a short time frame.
6. Testable: A user story should include criteria that allow it to be tested.

By adhering to these principles, you can write clear and detailed user stories.

4. User Story Writing Practice: Good vs Bad Examples

Bad Example:

User Story: “As a user, I can sign up.”

This is too vague. It’s unclear why the user needs to log in, and the goal, acceptance criteria, and value are not clearly defined.

Good Example:

User Story: “As a user, I can sign up using my email and password. The sign-up process requires email confirmation via a link. This prevents the use of fake or invalid email addresses.”

Acceptance Criteria:

1. Only verified email addresses can be used for login after the user receives the confirmation link.
2. The password must be at least six characters long and include a combination of letters and numbers.

This example clearly explains what the user wants and the benefits they will gain. It’s important to write user stories that are both specific and clear.

This introduces a new concept: Acceptance Criteria. Acceptance criteria are necessary to determine when a user story is considered complete. They set out the conditions that must be met for the story to be considered successful. These criteria align expectations between the development and business teams and provide a basis for testing whether the developed feature meets user needs.

5. Conclusion

Through user stories, the development team defines the features, breaking them down into smaller tasks and prioritizing them. This incremental approach allows for development to be more flexible, and requirements can be adjusted as needed.

User stories play a crucial role in backlog management, especially when epics are broken down into smaller user stories to be worked on step by step.

By effectively using user stories, epics, and acceptance criteria, even non-experts can define requirements relatively easily, and development teams can proceed with clarity. User stories, in particular, are well-suited for adjusting to changes in business or customer needs, allowing for flexible management. While the level of output and requirement management may differ from that of professionals, even inexperienced decision-makers or CEOs can learn and apply this approach in a short period of time. Now, you can introduce user stories into your projects to enhance communication during development and achieve your business goals.