In my previous articles, we have discussed Agile Story Point EstimationandAgile Story Point Estimation Techniques - Planning Poker. In this article, we will learn Story Point Estimation using T-Shirt Size Technique.
What is T-shirt sizing?
T-shirt Sizing is one of the Story points sizingtechnique to estimate user story usually used in agile projects. It's a relative Estimation Technique.
Rather than using a number of planning pokers, here, Items are classified into t-shirt sizes: XS, S, M, L, XL.
The term originates from the way T-shirt sizes are indicated in the US. Rather than having T-shirts in sizes 4, 5, 6 etc, there are just a few sizes: Small (S), Medium (M), Large (L) and Extra Large (XL) and so on.
With T-shirt measuring, the development team is made a request to evaluate whether they think a story is extra-small, small, medium, large, extra-large, or double extra-large. By expelling the numerical score, the development teamis allowed to think in a more dynamic manner about the exertion associated with a story. The sizes can, if necessary, be given numerical value after the estimation is finished.
Image Source:http://www.deltamatrix.com/agile-estimation/
Steps
- Make S, M, L, XL Cards
- Product Owner will explain the story to be estimated and the development team will ask questions if they have any issues or unclarity. For example,
- Design Related- Do we have to learn new things before starting the design/HTML/jQuery etc?
- Coding Related- Do we have any code class library ready or we have to write it from the scratch?
- Testing Related- Any specific setup required for Unit testing?
- Each developer gives each story a t-shirt size.
- All in Development team will raise their cards simultaneously.
- The development team will discuss the differences.
- The product owner explains the story further or clarifies misunderstanding if any.
- The team will Go back to Step 3-Step5 until all are agree with one size.
- Complete or place the stories in size buckets.
- Estimate the time to complete all stories in S,M, L, XLbuckets.
Image source :https://www.slideshare.net/agiledad/agile-estimating-planning
Benefits
- This is a very informal strategy and can be utilized quickly with a large number of items.
- It is a popular agile relative estimation technique.
- Forcing the estimate into one of a fixed set of sizes allows the process to go quickly
- It is a good way to Introduce terms to relative estimating.
- It is very effective for affinity estimating
T-shirt sizes can be a great way to becoming familiar with relative estimating. So, start with them if your dev team finds that easier.
But However, insignificantly put some fundamental numbers on them (e.g., Medium=5) and after that steadily shift to using the numbers directly.
I hope you like this article. stay tuned for more article on Agile Development. If you have any query, please feel free to post in the comments section.
Reference
- http://www.deltamatrix.com/agile-estimation/
- https://www.mountaingoatsoftware.com/blog/estimating-with-tee-shirt-sizes
- https://blogs.msdn.microsoft.com/oldnewthing/20090512-00/?p=18293
- https://www.slideshare.net/agiledad/agile-estimating-planning
