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Scrum
PSM-1 Certification
Scrum Planning and Estimation
Estimation Techniques
Summary

Summary: Scrum Planning and Estimation Techniques

<a className="txt-link" href="https://www.teachingAgile.com/about">Abhay Talreja</a>

By Abhay Talreja

2/5/2026

My latest article - Empirical Process Control - The Key to Agile Success

In this course, we've covered all essential estimation techniques used in Scrum Planning and Estimation. These techniques help Scrum Teams effectively plan, estimate, and forecast their work, ensuring the timely and successful delivery of valuable product increments. Let's recap the key aspects of each technique:

Comparison of Techniques

TechniqueBest ForSpeedAccuracyTeam Maturity
Planning PokerComplex items, new teamsSlowHighAny
T-Shirt SizingQuick rough estimatesFastMediumAny
Affinity EstimationLarge backlogsVery FastMediumAny
Story PointsSprint Planning, velocity trackingMediumHighIntermediate+
Relative EstimationComparing items to each otherFastMedium-HighAny
Ideal DaysStakeholder communicationMediumMediumBeginner
Fibonacci SequenceSizing scale for story pointsN/AHighAny

Planning Poker

  1. Collaborative and consensus-based: Planning Poker encourages collaboration and communication within the Scrum Team and helps them reach a consensus on effort estimates for Product Backlog Items (PBIs).

  2. Reduced bias and increased accuracy: Planning Poker minimizes the risk of anchoring bias and involves the entire team in the estimation process, resulting in more accurate estimates.

  3. Steps: Select a PBI, discuss the PBI, estimate independently, reveal estimates, discuss differences, and repeat until consensus is reached.

T-Shirt Sizing

  1. Simple and intuitive: T-Shirt Sizing offers a straightforward method for estimating effort by assigning relative sizes (XS, S, M, L, XL, XXL) to PBIs.

  2. Quick estimation and reduced pressure: T-Shirt Sizing enables quick estimation of relative effort, allowing the team to focus on actual development work.

  3. Steps: Select a PBI, discuss the PBI, assign T-Shirt Sizes, reach consensus, continue with remaining PBIs, and optionally convert sizes to numeric values if desired.

Affinity Estimation

  1. Grouping and relative comparison: Affinity Estimation involves grouping PBIs based on their relative effort, promoting a more efficient and accurate estimation process.

  2. Collaborative and visual: Affinity Estimation encourages collaboration among the team and provides a visual representation of the effort required for each PBI.

  3. Steps: Prepare the PBIs, conduct a silent sort, discuss and adjust the groupings, and assign effort estimates to each group.

Story Points

  1. Abstract relative unit: Story Points measure the overall effort considering three dimensions - complexity, uncertainty, and volume of work - without tying estimates to hours or days.

  2. Velocity-driven forecasting: Teams track how many story points they complete per Sprint (velocity), enabling data-driven Sprint Planning and release forecasting.

  3. Key principle: Story Points are team-specific and should never be compared across teams or used as a performance metric.

Relative Estimation

  1. Comparison-based approach: Rather than estimating items in absolute terms, teams compare items to each other - "Is this story bigger or smaller than that one?"

  2. Cognitive advantage: Humans are naturally better at relative comparison than absolute measurement, making this approach faster and more accurate.

  3. Foundation for other techniques: Relative estimation is the underlying principle behind Story Points, T-Shirt Sizing, and Affinity Estimation.

Ideal Days

  1. Time-based relative unit: An ideal day represents one full day of focused, uninterrupted work - no meetings, no emails, no context switching.

  2. Focus factor conversion: Teams use a focus factor (typically 0.6-0.7) to convert ideal days to calendar days for planning purposes.

  3. Stakeholder-friendly: Ideal days are more intuitive for non-technical stakeholders than abstract units like story points.

Fibonacci Sequence

  1. Proportional scale: The Fibonacci sequence (0, 1, 2, 3, 5, 8, 13, 21...) provides a scale where gaps increase with size, reflecting greater uncertainty for larger items.

  2. Prevents false precision: The increasing gaps force teams to choose between distinct values, avoiding debates over insignificant differences.

  3. Usage: Commonly combined with Planning Poker to estimate story points during Sprint Planning.

Choosing the Right Technique

  • Use Planning Poker when your team needs deep discussions about complexity and you have time for detailed estimation.

  • Use T-Shirt Sizing when you need quick, rough estimates, especially for initial backlogs or with non-technical stakeholders.

  • Use Affinity Estimation when you have a large backlog that needs to be sized quickly or when forming a new team.

  • Use Story Points when your team is comfortable with relative estimation and wants to track velocity for forecasting.

  • Use Relative Estimation as your foundation - understand this concept first, then choose a specific technique.

  • Use Ideal Days when transitioning from hour-based estimation or when stakeholders need a more intuitive unit.

  • Use the Fibonacci Sequence as your estimation scale in combination with other techniques like Planning Poker.

By understanding and applying these Scrum Planning and Estimation techniques, Scrum Teams can enhance their collaboration, communication, and estimation accuracy. This leads to better planning, forecasting, and ultimately, more successful product development.

Fibonacci SequenceScrum Implementation