.

7.8 Relative Estimation

How Relative Estimation Works

The Scrum Team selects a reference User Story and compares other stories against it.

Example

Reference Story:

• User Login → Small complexity

Now the team compares:

• Password Reset → Slightly larger
• Payment Gateway Integration → Much larger
• Shopping Cart → Medium complexity

The team estimates stories relative to the reference story.

Factors Considered in Relative Estimation

Factor	Description
Complexity	Difficulty of implementation
Effort	Amount of work involved
Risk	Uncertainty and unknowns
Dependencies	External system or team dependencies
Technical Challenges	Advanced technical requirements

Common Relative Estimation Techniques

Technique	Description
Story Points	Numeric relative estimation
Planning Poker	Consensus-based estimation game
T-Shirt Sizing	Size-based estimation categories
Affinity Estimation	Grouping similar-sized stories
Bucket System	Organizing stories into estimation groups

Story Points and Relative Estimation

Story Points are one of the most common forms of Relative Estimation.

Example:

User Story	Story Points
User Login	2
Password Reset	3
Payment Integration	8

This means:

• Payment Integration is much more complex than User Login

The points represent relative effort, not exact hours.

Relative Estimation vs Absolute Estimation

Aspect	Relative Estimation	Absolute Estimation
Measurement	Comparison-based	Exact hours/days
Focus	Relative complexity and effort	Precise time prediction
Accuracy	Better for Agile uncertainty	Often less accurate
Flexibility	Highly adaptable	Rigid estimation approach
Collaboration	Strong team discussion	Often individual estimation

Benefits of Relative Estimation

Benefit	Description
Improved Accuracy	Better handling of uncertainty
Reduced Estimation Pressure	Avoids exact time prediction stress
Better Team Collaboration	Encourages discussion and consensus
Supports Agile Planning	Improves Sprint Planning and forecasting
Improved Predictability	Velocity supports future planning
Faster Estimation Process	Quick comparison-based estimation

Relative Estimation and Velocity

Velocity measures how many Story Points the team completes during a Sprint.

Example

Sprint 1:

• Completed 20 Story Points

Sprint 2:

• Completed 22 Story Points

Average Velocity:

• 21 Story Points per Sprint

This helps teams estimate future sprint capacity.

Role of Product Owner in Relative Estimation

The Product Owner:

• Explains User Stories
• Clarifies business requirements
• Answers team questions
• Supports backlog refinement

The Product Owner usually does not assign estimates directly.

Role of Developers in Relative Estimation

Developers:

• Estimate User Stories
• Analyze technical complexity
• Evaluate effort and risks
• Collaborate on consensus estimates

Role of Scrum Master in Relative Estimation

The Scrum Master:

• Facilitates estimation sessions
• Encourages collaboration
• Supports Agile estimation practices
• Helps resolve estimation conflicts

Common Challenges in Relative Estimation

Challenge	Description
Unclear User Stories	Difficult to compare accurately
Inconsistent Reference Stories	Different comparison standards
Large User Stories	Complex stories difficult to estimate
Converting Estimates to Hours	Misunderstanding relative estimation
Team Disagreement	Different views on complexity

Best Practices for Effective Relative Estimation

• Use reference stories consistently
• Estimate collaboratively
• Keep stories small and refined
• Focus on comparison, not exact time
• Encourage open discussion
• Review velocity regularly

Common Mistakes in Relative Estimation

• Converting Story Points into hours
• Comparing velocities between teams
• Estimating without discussion
• Using estimation for employee evaluation
• Ignoring uncertainty and risks

Relative Estimation in Agile Planning

Relative Estimation supports:

• Sprint Planning
• Release Planning
• Roadmap Forecasting
• Capacity Planning
• Velocity Tracking

Real-Life Example

Example:

A Scrum Team estimates the following User Stories:

• User Login → Small effort
• Shopping Cart → Medium effort
• AI Recommendation Engine → Very large effort

Instead of estimating exact hours, the team compares each feature relative to previously completed stories and assigns Story Points accordingly.

Importance of Relative Estimation in Agile

Relative Estimation is important because it:

• Supports Agile adaptability
• Improves planning realism
• Encourages collaboration
• Handles uncertainty effectively
• Improves sprint predictability

Conclusion

Relative Estimation is a powerful Agile estimation approach that helps Scrum Teams estimate work based on comparison instead of exact time prediction.

By focusing on complexity, effort, risk, and relative size, Relative Estimation improves collaboration, estimation accuracy, sprint planning, and overall Agile delivery success.