Affinity Estimation

Affinity Estimation is a very quick technique to help size backlog items with a rough rule of thumb approach, which is ideal when you have a lot of items to size or are creating a backlog of work for the first time.

Steps

1. Arrange the sizing categories along the top in a row, (can be done on a wall, floor or on a virtual board.)
2. Select an item that is relatively small compared to other items as the first item to estimate and place it under one of the lower sizing categories
3. Select the next item and relative to the first item place it in one of the corresponding sizing categories, choosing whether it is less, more or about the same effort to complete as the first item
4. Select the next item and relative to the two previously sized items choose a corresponding sizing category, and repeat until all of the cards have been placed in sizing categories
5. Next look over all of the cards and adjust as necessary to make the final cut
6. Lastly write on the cards the size that they were allocated to

80:20 Rule

This technique is great for quick sizing of a number of cards, and it is useful to consider that the estimation is good enough with an 80:20 rule, that is, 80% accuracy with 20% of the effort to do the sizing.

Working With Large Groups

When working with large groups you might like to make the following modifications to the steps:

• Allow everyone in the group to take a number of cards from the stack
• Each member of the group sizes their collection of cards individually first
• When all of the cards have been allocated to a sizing category, then work as small groups e.g. pairs or triads to look over the cards and adjust as necessary.

See Also

• Agile Estimation
• T-Shirt Sizing
• Story Mapping