Estimating Tasks with T-shirt Sizes

January 28, 2015

"The Fibonacci sequence and the Mountain Goat modified sequence for Planning Poker (1, 2, 3, 5, 8, 13, 20, 40) are great intervals for Story Point estimation. It's a great interval for determining the relativity of one backlog item (or user story) to another backlog item. However, these two intervals are cumbersome when it comes to estimating the time it takes to complete tasks associated with a backlog item.  So, the next time you are in your Sprint Planning meeting and you have already planned out the WHAT and you're ready for the HOW, try T-shirt sizing for task estimates.

Remember that the Sprint Planning meeting can be broken into two sections. The WHAT and the HOW.

The first section of Sprint Planning, the WHAT, is what Backlog Items are we planning to bring into the Sprint. This involves the whole Scrum team, including the Product Owner. Second, the HOW is creating the tasks required to fully complete (per your Definition of Done) each Backlog Item. When you have finished tasking all Backlog Items, look back at the Sprint Backlog and commit/forecast the Backlog Items you plan to complete for this Sprint. While your estimates for the Backlog should be relatively measured against each other with Story Points, estimates for tasks can be loosely relative and based on the hours it will take to complete the task. If you play Planning Poker with the intervals mentioned above, you may have unnecessary arguments on close estimates. Try this new approach...

T-shirt for Tasks

  • SM - Small - 2 hours worth of work
  • MD - Medium - 4 hours worth of work (1/2 day)
  • LG - Large - 8 hours worth of work (full day)
  • XL - Extra Large - too large to complete in one day, break into smaller tasks!

In the Estimated app, you can change the table's card format. If you're in the real-world and you don't want to download an amazing App, AND you don't want to use the Estimated Mobile Offline Version, you could create the cards manually. Good luck and happy estimating! Let me know if you have tried this technique and found success, comment below!"