Story points: Fibonacci, Poker, Agile

Story points

Story points estimate the relative size of a user story.

They consider:

  • effort,
  • complexity,
  • uncertainty,
  • technical risk,
  • dependencies.

Story points do not directly mean hours or days.

A 5-point story is expected to be larger or more uncertain than a 3-point story, but it does not necessarily take exactly five hours or five days.

Fibonacci scale

use the Fibonacci-style sequence:

1, 2, 3, 5, 8, 13

The gaps become larger because uncertainty increases with larger work.

PointsTypical interpretation
1Very small, clear, little risk
2Small and well understood
3Moderate effort
5Larger, some complexity or uncertainty
8Complex, risky, or dependent on other work
13Very large or unclear; may need to be split

Example

For the Cart and Checkout feature:

User storyPossible estimateReason
Remove an item from the cart2Small, clear behavior
Update item quantity3Includes validation and total recalculation
Apply a promo code5Requires business rules and error handling
Complete checkout8Multiple steps and cross-team dependencies
Build the complete cart-and-checkout flow13Too broad; should probably be split

Planning poker

Planning poker is a collaborative estimation technique.

Each team member privately chooses a Fibonacci card for the story. Everyone reveals their estimate at the same time.

Process

  1. The Product Owner explains the user story and acceptance criteria.
  2. Team members ask questions.
  3. The team discusses effort, complexity, uncertainty, and dependencies.
  4. Each member privately selects a point value.
  5. Everyone reveals their value simultaneously.
  6. The highest and lowest estimators explain their reasoning.
  7. The team discusses the differences.
  8. Everyone estimates again.
  9. The process continues until the team reaches consensus or close agreement.
  10. The final estimate is recorded in Jira.

Example planning-poker discussion

Story:

As a customer, I want to apply a promotional code so that I can receive a discount.

Initial estimates:

  • User A: 3
  • User B: 5
  • User C: 8
  • User D: 5

Discussion:

  • The User choosing 3 assumed only one simple code.
  • The User choosing 8 considered expiration dates, usage limits, invalid codes, and payment integration.
  • After reviewing the acceptance criteria, the team agrees that the story has more complexity than first assumed.

Final estimate:

5 story points

Important teaching points

  • Story points are assigned by the team, not only by the Product Owner.
  • Planning poker is not a simple average.
  • The goal is shared understanding, not mathematical precision.
  • A large disagreement often reveals hidden assumptions.
  • A 13-point story should usually be reviewed and possibly divided into smaller stories.
  • Teams should not compare their story-point scale with another team’s scale.

Teaching line

Fibonacci gives the team an estimation scale. Planning poker gives the team a method for reaching a shared estimate.

REF: AI Tools/ChatGPT

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