The Product Backlog is an ordered list of hypotheses, requirements, features, enhancements, or Product Backlog Items that help the team accomplish the Product Goal.
The Product Backlog is the team’s single source of work. Meaning, anything the Developers are working on should be coming from the Product Backlog. There are no side requests. Any work should go through the Product Owner who determines its relevance and importance and places it in the Product Backlog for the team to work on.
The Product Backlog is dynamic, always changing, frequently reordered, and never complete. Why? Because Scrum is all about empiricism. Knowledge comes from doing the work, gaining experience, and then making decisions based on what is learned. Meaning, from the start the team is saying we don’t know everything. This is what we currently know today and what we think we should do. As we work, we expect to learn more and based on that, we expect this list to change accordingly. The Product Owner is always re-ordering the Product Backlog and ensuring the most important items are towards the top.
At any point in time, if you take a picture of the Product Backlog, it is going to look like this. Towards the top, the Product Backlog consists of fine-grained Product Backlog Items. These are items that have been reviewed, clarified, estimated, and broken down into very small items that are considered “Ready” for the next Sprint and can get pulled into the Sprint Backlog and tasked out in Sprint Planning.
Towards the middle, the Product Backlog Items are less refined, a bit larger, and require clarification before being worked on.
Towards the bottom, the Product Backlog Items are large concepts or ideas that are vague, not yet well thought out, and require a lot of clarification before being worked on.
The Product Backlog will always look like this, with mostly fined-grained items towards the top and coarse-grained items towards the bottom. It will look like this on day 5, on day 25, on day 50, and on day 250. Why? Because as the top items that are “Ready” to be worked on get pulled into the Sprint Backlog, the items below them, move up and get broken down and clarified, and the items below them also move up and get broken down and clarified and so forth, doing this just in time and at the right level of granularity. This happens in Product Backlog Refinement and is referred to as progressive elaboration where we clarify the upcoming work as we are getting closer and closer to working on it.
Product Backlog Refinement is an ongoing activity that occurs throughout the Sprint. It is not a timeboxed event. Just as the team dedicates time during the Sprint to build a product increment, the team also dedicates time to do ongoing Product Backlog Refinement. Refinement involves the Scrum team, with the key conversation happening directly between the Product Owner and Developers.
The Product Owner decides where a new Product Backlog Item might go, whether it goes towards the top, middle, or bottom based on its relevance and importance, always keeping the Product Goal in mind.
At any point in time, the Product Owner might drop an item deemed no longer important or necessary.
Throughout, the Product Owner regularly re-orders the Product Backlog based on the latest information and knowledge gained.
The Developers seek clarification, research, estimate, identify risks, and break items down into more manageable chunks of work so that by the time the items reach the top of the Product Backlog, they are “Ready” to be worked on.
This is Product Backlog Refinement, an ongoing activity that the Scrum team does throughout the Sprint to add, remove, reorder, clarify, research, estimate, split, or merge Product Backlog items to progressively elaborate on them so that the items towards the top of the Product Backlog are always ready for the next Sprint. Because when one Sprint ends, the next one starts. There are no breaks in between to figure out what to work on next. It’s the Ready items on the top of the Product Backlog.
For more details, sign up for an upcoming foundational Certified Scrum Developer® (CSD®) class, or a Certified Product Owner® (CSPO®) class, or ScrumMaster® (CSM®) class.