Planning Poker is a very effective Product Backlog estimation technique and the most common method is using Fibonacci numbers (1,2,3,5,8,13, etc.)
TIP: If User Stories are estimated at more than one day of work, consider splitting them into smaller pieces to keep them under one day. See
Do You Break Large Tasks into Smaller Tasks?
TIP: If you do find a very large User Story, consider using a Spike (aka. an investigation task) to help work out how much work will be involved.
Figure: Bad example - Estimation using T-Shirt sizes
Figure: OK example - Estimation using Planning Poker with large numbers
Figure: Good example - Estimation using Planning Poker with only small numbers
Guidelines for Estimating User Stories
Every team is different, but you can use the following guidelines for sizing User Stories.
| Estimate Value |
Example User Story |
| 1 |
A change to a messagebox |
| 2 |
|
| 3 |
A timeboxed task for 1 day x 1 guy |
| 5 |
A timeboxed task of 1 day x 2 guys |
| 8 |
|
| 13 |
|
| 21 |
More than a month with a couple of guys.
TIP: Don't include these in a sprint because they are too risky - ask for them to be broken down. |
Figure: Good example - Example User Story estimatesTIP: If you are working on a project with a remote team, use IM to size stories using Planning Poker. Everyone should give their points for stories at the same time to avoid influencing each other. Another method of estimating is the "Fist method". This is particularly useful if you don't have Planning Poker cards. Instead of Fibonacci numbers, estimates are from 1 to 5. It's nice and simple, and you only need the fingers on your hand.
Figure: User Story estimates using the "Fist method"