Product backlog

What it means

A backlog is an ordered list of everything a team is to work on in the future: new features, bug fixes, technical tasks or improvements. The most important items sit at the top and are described in detail; less important ones are lower down with just a brief note.

In Scrum the product backlog is managed by the product owner, who decides the order based on value to customers and the company. At the start of each sprint the team picks from the top of the backlog what it can complete in the coming weeks.

Items are usually written as user stories with acceptance criteria. A backlog is never a finished document but a living list that is constantly added to, refined and cleared of items that no longer make sense.

How it works in practice

Backlogs are not only for software development. An accounting firm can use one to run a system rollout, process automation or service improvements, giving every client request or team idea a place and a priority.

Regular backlog grooming or refinement is a meeting where items are clarified, effort is estimated and priorities change. Without it a backlog quickly turns into a chaotic store of ideas.

In outsourced development the backlog lets both client and supplier see what is being done and why. Under a time and material contract it is the client's main tool for steering what it pays for.

What to watch out for

The most common problem is a backlog with thousands of items, most of which will never be built. The team gets lost and important things disappear, so old and unneeded items should be deleted boldly.

If the order changes every day depending on who pushes hardest, the team finishes nothing. One responsible person should set priorities, and changes during a sprint should be the exception.