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Alternative Estimation Methods

Learning Objectives

By the end of this lesson you will be able to:

  • Describe T-shirt sizing and when to apply it
  • Explain the #NoEstimates movement's core argument
  • Facilitate an Affinity Mapping estimation session
  • Choose between estimation methods based on team maturity and project phase

Why Alternatives Exist

Planning Poker is a good default. But it's not the only tool, and it's not always the best one. Different situations call for different approaches:

  • Early exploration: You need rough sizing, not precise estimates
  • Large backlog grooming: You need to size 50+ stories quickly
  • Team dysfunction: Planning Poker itself has become the source of conflict
  • High-trust, mature teams: The overhead of formal estimation outweighs the benefit

Method 1: T-shirt Sizing

Instead of Fibonacci numbers, use sizes: XS, S, M, L, XL, XXL.

How it works:

  • Each size represents a rough relative bucket, not a precise number
  • Teams first agree on a "reference story" for each size (e.g., "An M is about as complex as adding a new filter to the search page")
  • Stories are then placed into buckets relative to the references

When to use it:

  • Initial roadmap estimation (months out, when precision is meaningless)
  • Backlog grooming for a large, newly prioritized batch of stories
  • With stakeholders who don't have context on Story Points

Limitation: T-shirt sizes don't aggregate easily. You can't directly compute sprint capacity. The usual solution is to map sizes to points for planning purposes (e.g., S=2, M=5, L=8, XL=13).

Pro Tip: T-shirt sizing works best when you resist the urge to be precise. "Is this an M or an L?" should take 30 seconds, not 10 minutes. If you're spending more than that, the story needs refinement, not better estimation.

Method 2: #NoEstimates

The #NoEstimates movement argues that for many teams, the cost of estimation (time, meetings, false precision) exceeds the value. Instead of estimating story points, teams:

  • Count stories (assuming roughly similar size after good slicing)
  • Use Cycle Time averages to forecast: "We close ~8 stories per sprint; we have 40 stories left; ~5 sprints to complete"
  • Focus refinement energy on slicing stories to similar sizes rather than assigning numbers

When it makes sense:

  • Mature teams with strong slicing discipline
  • High-certainty backlogs where stories are consistently well-defined
  • When historical data (Cycle Time, throughput) is available for forecasting

When it doesn't make sense:

  • New teams without historical data
  • Teams where story sizes vary wildly
  • Contexts where stakeholder communication requires point-based forecasts

The nuanced view: #NoEstimates isn't anti-forecasting. It's anti-fake-precision. Using count + Cycle Time for forecasting is still forecasting — just with metrics that have less noise.

Method 3: Affinity Mapping

A fast, high-participation method for sizing a large backlog.

How it works:

  1. Write each story on a card (sticky note or digital card)
  2. One person places the first card somewhere on a spectrum (left = small, right = large)
  3. Each subsequent card is placed relative to the existing ones: "Is this bigger or smaller than X?"
  4. No discussion during placement — just silent relative ordering
  5. After all cards are placed, the group draws lines to create buckets (these become your size groups)
  6. Discussion only happens when someone disagrees with a placement

Why it's fast: Most estimation time is spent debating. Affinity Mapping uses silent parallel processing — everyone moves cards at once or takes turns quickly without discussion. A team of 6 can size 40 stories in 30-40 minutes.

When to use it:

  • Sprint 0 / project kickoff
  • Quarterly planning with a new batch of epics
  • When Planning Poker would take too long for the volume of items

Choosing the Right Method

Situation Method
New team, first sprint Planning Poker (builds shared understanding)
Large batch, rough sizing T-shirt Sizing or Affinity Mapping
Mature team with good data #NoEstimates / throughput forecasting
Backlog has wild size variation Fix the slicing first, then any method works
Planning Poker debates consuming sessions Affinity Mapping or T-shirt Sizing

Summary

Estimation methods are tools, not religions. Planning Poker is a useful default that builds shared understanding. T-shirt sizing is faster for rough cuts. Affinity Mapping scales to large batches. #NoEstimates makes sense when you have the data and discipline to replace story points with throughput metrics. The best teams try multiple approaches and keep what works.

Quiz

In T-shirt sizing, what is the purpose of defining "reference stories" for each size?

A mature team has 18 months of sprint history, consistent story slicing, and an average Cycle Time of 2.5 days per story. Which approach fits best?

What is the key difference between Affinity Mapping and Planning Poker?

The #NoEstimates approach is described as "anti-fake-precision." What does this mean?