On Magic Estimations

Introduction

What if you could estimate about 40 Stories in just 10 minutes?
“Impossible!” you say? Well then – read on!

What are estimations really?

They are an attempt to guess what the future will bring based on a multitude of factors such as experience, hard data, gut feelings and the likes. Estimations are also always wrong. How much depends on the subject and the person or group estimating. But nevertheless they give us a valuable guideline and basis to do a conversation.

With that established let’s take a look at Magic Estimation, originally introduced by Boris Gloger on the South African Scrum Gathering.

Idea behind Magic Estimation

As established estimations are usually wrong but a valuable guideline. However time spent on estimations helps do the right things in the right order but does not directly contribute towards the project goal. A team can be very busy for months estimating this and that and not produce a single line of code. Magic Estimation tries to harness the wisdom of the crowd to quickly estimate a large backlog – and by quickly I mean “within minutes”. It therefore reduces the time spent on estimations while retaining their value.

Prerequisites

You’ll need a backlog that has stories in a shape that they can be (at least roughly) estimated. Following the “Story Maturity” method described in an earlier article of mine can help you with that. Apart from that you’ll need a team of five to ten people and 15 minutes of time.

How-To

  1. Print out all stories (one per piece of paper) or fetch the story cards currently in our backlog – it’s important to use paper. This will not work using a computer.
  2. Shuffle the stories and put them on a stack face-down
  3. Prepare a table where you designate areas to a specific story point. You could start with a “1” area and then go upwards. The idea is that people can place the story cards in that specific area to indicate their estimation
  4. For the next 5 minutes follow steps 5 to 9
  5. Every team member picks up a story from the stack
  6. IN COMPLETE SILENCE quickly skims the story and decides in which area on the story point scale to put it
  7. NO DISCUSSIONS
  8. Whoever placed his/her story picks up a new one from the stack
  9. Repeat until all stories are placed
  10. Write the current estimation on the story paper
  11. IN COMPLETE SILENCE everyone can move any number of stories to a new location (**)
  12. As soon as the story was moved strike-through the prior estimation on the story paper and write the new one down
  13. Do this for 5 minutes
  14. Collect results

(**) As an alternative of moving the stories around you can also shuffle the stories into a new stack and repeat from step 5.

Collecting results

Stories that have only one or two estimates (with one crossed out) on them will retain that estimation for this session.

Stories that have more than two estimates on them will be gathered and need to be looked over, as there seems to be widespread disagreement on the effort required. You can schedule the discussion for a later date or address it directly.

And with that you’re done!

The Bottom Line

Magic Estimation allows you to quickly get estimations for a large stack of backlog items. These estimations are rough – yes – but they will give you a feeling where you are with your project.

They can also trigger a lot of healthy discussions without spending too much time on backlog grooming – giving you more time to work on you project instead of sitting in meetings.