User Stories and Estimation

User stories and estimation techniques help Agile teams describe what needs to be built and forecast how long it will take. While neither is prescribed by the Scrum Guide, both are widely used by Scrum and Agile teams to manage their Product and Sprint Backlogs effectively.

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What is a User Story?

A user story is a short, simple description of a feature or requirement told from the perspective of the person who desires the new capability — usually a user or customer.

The Standard Format

As a [type of user],
I want [an action or feature],
So that [a benefit or value].

Examples

User Story	Explanation
As a shopper, I want to filter products by price, so that I can find items within my budget	E-commerce filtering feature
As a manager, I want to export reports to PDF, so that I can share them with stakeholders offline	Reporting feature
As a new user, I want to reset my password via email, so that I can regain access to my account	Account recovery feature

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The Three Cs

Ron Jeffries described the three components of a user story:

Component	Description	Example
Card	The physical or digital card with the story written on it	"As a shopper, I want to filter by price..."
Conversation	The discussion between the team and Product Owner to clarify details	"What price ranges should we support? What about currency?"
Confirmation	The acceptance criteria that define when the story is Done	"Given a price range is selected, when I click filter, then only matching products appear"

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Acceptance Criteria

Acceptance criteria define the conditions that must be met for a user story to be considered complete. They provide clarity and prevent misunderstandings.

Given-When-Then Format

Given [a precondition],
When [an action is taken],
Then [an expected result occurs].

Example

For the story: As a shopper, I want to filter products by price

#	Criterion
1	Given I am on the product listing page, when I set a minimum and maximum price, then only products within that range are displayed
2	Given I have applied a price filter, when I clear the filter, then all products are displayed again
3	Given no products match the price range, when I apply the filter, then a "no results" message is shown

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INVEST Criteria

Good user stories follow the INVEST criteria:

Letter	Criterion	Description
I	Independent	The story can be developed and delivered without depending on other stories
N	Negotiable	Details can be discussed and refined; the story is not a rigid contract
V	Valuable	The story delivers value to the user or business
E	Estimable	The team can estimate the story's size or effort
S	Small	The story is small enough to be completed in a single Sprint
T	Testable	The story has clear acceptance criteria that can be verified

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Story Splitting Techniques

Large stories (called epics) need to be split into smaller stories. Common splitting strategies include: