Product Backlog Refinement
Purpose
Product Backlog Refinement (or Product Backlog Grooming) is an ongoing activity in Scrum projects. It is the act of reviewing and revising Product Backlog items, which typically involves adding detail, estimates, and order to them. The Product Owner is responsible for ordering (prioritizing) the items and the Development Team is responsible for estimating.
Timing
When the Product Owner adds a new item to the Product Backlog, or breaks down an existing item into smaller ones, s/he explains it to the Development Team and asks for estimates. Therefore, everyone knows the meaning of items before the Sprint Planning and the estimates are ready. What happens in the Sprint Planning is that they review those pieces of information, just to make sure that everything is OK.
Duration
As opposed to Scrum events, the Product Backlog Refinement is not timeboxed (it doesn't have a maximum duration). it is an ongoing activity that happens throughout the Sprint.
This activity should not consume more than 10% of the time of the Development Team.
External Resources
- Scrum Guide, a definition of the Scrum framework by Ken Schwaber and Jeff Sutherland
- Nexus Guide, a framework for scaling Scrum by Ken Schwaber et al.
- The Scrum Master Training Manual, a free ebook on Scrum, and the Professional Scrum Master™ (PSM™ I) exam
- Scrum Awareness, a free email course on Scrum framework