User Story Writing

# Acceptance Criteria Examples

## Acceptance Criteria Examples

```yaml
Story: As a customer, I want to save payment methods so I can checkout faster

Acceptance Criteria:

Scenario 1: Add a new payment method
  Given I'm logged in
  And I'm on the payment settings page
  When I click "Add payment method"
  And I enter valid payment details
  And I click "Save"
  Then the payment method is saved
  And I see a success message
  And the new method appears in my saved list

Scenario 2: Edit existing payment method
  Given I have saved payment methods
  When I click "Edit" on a method
  And I change the expiration date
  And I click "Save"
  Then the changes are saved
  And other fields are unchanged

Scenario 3: Delete a payment method
  Given I have multiple saved payment methods
  When I click "Delete" on a method
  And I confirm the deletion
  Then the method is removed
  And my default method is updated if needed

Scenario 4: Error handling
  Given I enter invalid payment information
  When I click "Save"
  Then I see an error message
  And the method is not saved
  And I'm returned to the form to correct

Scenario 5: Security
  Given the payment form is displayed
  When I view the page source
  Then I don't see full payment numbers (PCI compliance)
  And credit card data is encrypted
  And the connection is HTTPS

---
Non-Functional Requirements:
  - Performance: Form save must complete in <2 seconds
  - Usability: Form must be completable in <3 steps
  - Reliability: 99.9% uptime for payment service
  - Accessibility: WCAG 2.1 AA compliance
  - Security: PCI DSS Level 1 compliance
```


# Story Estimation

## Story Estimation

```yaml
Story Pointing Framework:

1 Point: Trivial
  - Update label text
  - Add CSS class
  - Simple config change
  - Time: <2 hours

2 Points: Very small
  - Add simple field to form
  - Update error message
  - Simple validation
  - Time: 2-4 hours

3 Points: Small
  - Create single page/component
  - Add basic API endpoint
  - Simple integration
  - Time: 4-8 hours

5 Points: Medium
  - Create feature with multiple interactions
  - Build API with multiple endpoints
  - Complex business logic
  - Time: 1-2 days

8 Points: Large
  - Feature spanning multiple pages
  - Complex integration
  - Multiple technical challenges
  - Time: 2-3 days

13 Points: Very large (TOO BIG - Split it!)
  - Should be split into smaller stories
  - Or elevated to epic
  - Time: >3 days

---

Estimation Tips:
  - Use relative sizing (compare to known stories)
  - Consider unknowns and risks
  - Include non-coding time (testing, docs)
  - Account for team skill level
  - Be transparent about assumptions
  - Re-estimate after learning
```


# Story Refinement Process

## Story Refinement Process

```python
# Story refinement and quality gates

class UserStoryRefinement:
    QUALITY_GATES = {
        'Independent': 'Story can be implemented independently',
        'Negotiable': 'Details can be discussed and refined',
        'Valuable': 'Delivers clear business value',
        'Estimable': 'Team can estimate effort',
        'Small': 'Can be completed in one sprint',
        'Testable': 'Clear acceptance criteria'
    }

    def evaluate_story(self, story):
        """Assess story quality using INVEST criteria"""
        assessment = {}

        for criterion, description in self.QUALITY_GATES.items():
            assessment[criterion] = self.check_criterion(story, criterion)

        return {
            'story_id': story.id,
            'assessment': assessment,
            'ready_for_development': all(assessment.values()),
            'issues': self.identify_issues(story),
            'recommendations': self.provide_recommendations(story)
        }

    def check_criterion(self, story, criterion):
        """Evaluate against specific INVEST criterion"""
        checks = {
            'Independent': lambda s: len(s.dependencies) == 0,
            'Negotiable': lambda s: len(s.acceptance_criteria) > 0,
            'Valu