Key Principle: Refine the Product Backlog

After the product backlog is initially populated, it needs to be “refined” on an ongoing basis so that each PBI contains enough detail to support effective sprint planning and development work. I typically want to see about two sprints’ worth of fully refined PBIs in the backlog at all times, not including the work in the current sprint.

Insufficient backlog refinement can cause a number of significant problems for the Agile team:

• The backlog items are not defined in sufficient detail to guide the work, so the team goes in the wrong direction.

• The team spends too much time refining during the sprint and encounters too many surprises as it goes.

• The backlog items have not been updated, so the team implements out-of-date concepts of the work.

• The backlog is not prioritized properly, so the team works on lower value items and delays work on more valuable items.

• Backlog items are misestimated and are too large, so the team cannot complete its sprint commitment because items were larger than expected.

• The team might be outright starved for work because there aren’t enough refined items in the backlog.

Backlog refinement sessions

Backlog refinement is done in a session that includes the Product Owner, Scrum Master, and the Development Team. The whole team attends so that a shared understanding can be developed of the upcoming work.

Work includes discussing stories and epics, splitting epics into stories, splitting stories into smaller stories (and splitting epics into smaller epics), clarifying details of stories, defining acceptance criteria for stories, and estimating stories.

Backlog refinement meetings are typically held mid-sprint. If questions need to be answered, the work to answer those questions should be done prior to the next sprint planning meeting so that open questions don’t undermine sprint planning.

The Product Owner brings a prioritized (ordered) list of PBIs to the backlog refinement session and should have already completed most of the requirements-related elaboration work.