Scrum Roles and Accountabilities
Three accountabilities, no sub-teams
The Scrum Team is one self-managing, cross-functional unit of ten or fewer people with three accountabilities.
Product Owner - maximizes value by managing the Product Backlog: clearly expressing items, ordering them, and ensuring the team understands them. The PO is one person, not a committee, and is accountable for the what and why. The PO may delegate work but remains accountable.
Scrum Master - accountable for the Scrum Team's effectiveness. Serves the team (coaching self-management, removing impediments), the Product Owner (helping with backlog technique and stakeholder collaboration), and the organization (leading Scrum adoption, removing friction between teams and stakeholders). The SM is a true leader who serves, not a project manager or a secretary.
Developers - the people committed to creating any aspect of a usable Increment each Sprint. They self-manage how to do the work and hold all technical accountabilities.
Traps to watch
- "Who decides?" The PO orders the backlog; the Developers decide how much they take on and how to build it; nobody tells them how.
- "Can the SM assign tasks?" No - that is self-management violated.
- "Can the PO attend the Daily Scrum?" May attend, but must not direct the Developers' plan.
- "Who can cancel a Sprint?" Only the Product Owner, and only if the Sprint Goal becomes obsolete.
- Titles like "team lead" or "proxy PO" are not Scrum accountabilities.
Rule of thumb
Match the decision to the accountability: value and ordering → Product Owner; how and how much → Developers; process, effectiveness and impediments → Scrum Master.
Worked example
A manager asks the Scrum Master to reassign developers to hit a date. Correct response: the SM coaches the manager on self-management and helps the Developers and PO re-plan through the backlog, rather than issuing assignments.