Story Slicing

Story slicing is the activity of taking large stories and splitting them into smaller, more predictable deliveries. This allows the team to deliver higher priority changes more rapidly instead of tying those changes to others that may be of lower relative value.

Recommended Practices

Stories should be sliced vertically. That is, the story should be aligned such that it fulfills a consumer request without requiring another story being deployed. After slicing, they should still meet the INVEST principle.

Example stories:

As an hourly associate I want to be able to log my arrival time so that I can be
 paid correctly.

As a consumer of item data, I want to retrieve item information by color so that
 I can find all red items.

Stories should not be sliced along tech stack layer or by activity. If you need to deploy a UI story and a service story to implement a new behavior, you have sliced horizontally.

Do not slice by tech stack layer

• UI “story”
• Service “story”
• Database “story”

Do not slice by activity

• Coding “story”
• Review “story”
• Testing “story”

Tips

• If you’re unsure if a story can be sliced thinner, look at the acceptance tests from the BDD activity and see if it makes sense to defer some of the tests to a later release.

• While stories should be sliced vertically, it’s quite possible that multiple developers can work the story with each developer picking up a task that represents a layer of the slice.

• Minimize hard dependencies in a story. The odds of delivering on time for any activity are 1 in 2^n where n is the number of hard dependencies.