Backlog refinement

Before a sprint can start, the sprint backlog needs to be defined. What stories need to go into the sprint? To provide an answer to that, the team needs to review the product backlog. The product backlog contains all actions (stories) that need to be taken to complete the product (the app). First, they need to be refined before the team can commit to them.

Each story needs an estimation of the amount of work involved. This estimation is usually expressed in story points, not hours. The story points relate to the expected complexity and amount of work. Typically, a specific and clear action such as Edit a text on a button will be defined as one story point. This creates an anchor for defining other more complex stories. All estimated stories will be derived from it.

To be able to assign story points, the story needs to be clear and well understood by the team. Planning poker is often used to let the team members make estimates. You can use cards for the estimates, or use one of the many apps that are available.

Here is an example of such an app, called Scrum Time. You can find it on the Play Store or App Store.

As a user of the app, you can pick a card with a number that you will show to the rest of the team. If the estimated points differ too much between the team members, then they need to discuss why they think the implementation and testing of a story will take more (or less) time. Perhaps a member of the team has knowledge that the rest do not have, or maybe he is looking at the story in a different way. New insights can contribute to a better estimation.

The numbers to pick from are typically derived from the Fibonacci sequence. In mathematics, the Fibonacci sequence is characterized by the fact that every number after the first two is the sum of the two preceding ones. The reason why these numbers are used here is that the larger a story becomes (having more story points), the more difficult it will be to make an exact estimation. If you have no clue, you can always play the question mark card, or if the action related to the story is infinite (think of delivering support), then there are cards for that as well. And yes, if you are thirsty, there is always the coffee/pause card that you can play.

The 1,2,3,5, and 8 cards are the ones that are played most often. Stories with more points very likely need to be split up into multiple smaller stories to reduce risk.