1. Planning Poker

Planning Poker is one of the most popular estimation methods in Scrum. It combines expert opinion, analogy, and team consensus.

How it works:

• Each team member is given a set of cards (typically with numbers in a Fibonacci sequence: 1, 2, 3, 5, 8, 13…).
  
• A user story is read out.
  
• Team members privately choose a card that represents their estimate.
  
• All cards are revealed at the same time.
  
• If estimates vary widely, the team discusses why, and re-votes until consensus is reached.
  

Best For:

• Teams of 5–10 members.
  
• Stories where team alignment is crucial.
  

Why It Works:

• Encourages conversation, not just numbers.
  
• Reduces anchoring bias where one person influences others.
  
  

2. T-Shirt Sizing

This technique is simple and ideal during initial backlog grooming or for high-level estimation.

How it works:

• Stories are assigned sizes like XS, S, M, L, XL, based on their relative effort and complexity.
  
• These sizes are later mapped to actual story points or time estimates.
  

Best For:

• High-level estimations.
  
• Early-stage projects.
  

Why It Works:

• It’s fast and avoids early commitment to precise numbers.
  
• Helps prioritize work without over-analyzing.
  

3. Fibonacci Sequence

The Fibonacci Sequence is often used in Planning Poker, but it can also stand alone as a way to estimate relative complexity.

How it works:

• Use Fibonacci numbers (1, 2, 3, 5, 8, 13, etc.) to represent effort or complexity.
  
• The jump between numbers reflects increased uncertainty and complexity.
  

Best For:

• Teams familiar with relative sizing.
  
• Medium to large backlogs.
  

Why It Works:

• • The gaps between numbers force discussion.
    
• Makes it easier to identify outliers or overly complex stories.
  

4. Bucket System Estimation

This technique is helpful for estimating a large number of user stories quickly.

How it works:

• Create “buckets” labeled with story points (1, 2, 3, 5, etc.).
  
• Each user story is discussed briefly and placed into the appropriate bucket.
  
• If there’s disagreement, discuss and reassign.
  

Best For:

• Large backlogs or release planning.
  
• Time-boxed estimation sessions.
  

Why It Works:

• It’s faster than one-at-a-time methods like Planning Poker.
  
• Great for remote teams and workshops.
  

5. Dot Voting

Also known as multi-voting, this technique allows team members to vote on story priorities or effort levels.

How it works:

• Each team member gets a set number of “dots” (votes).
  
• User stories are displayed on a board.
  
• Members vote by placing dots on the stories they think are most effort-intensive or high-priority.
  
• Stories with the most votes are discussed first.
  

Best For:

• Prioritizing the backlog before estimation.
  
• Large teams or stakeholder reviews.
  

Why It Works:

• Encourages collaborative prioritization.
  
• Easy to implement in physical or virtual settings.
  

6. Three-Point Estimation (PERT)

This technique uses three estimates to calculate an average, helping account for uncertainty.

How it works:

• Optimistic Estimate (O): Best-case scenario.
  

• Pessimistic Estimate (P): Worst-case scenario.
  

• Most Likely Estimate (M): Expected case.
  

Use the formula:
(O + 4M + P) / 6

Best For:

• • Complex or high-risk stories.
    

• Projects where accurate time estimation is critical.
  

Why It Works:

• • Provides a more realistic estimate by considering uncertainty.
    
• Great for risk management.