HKSM

A blocker is a specific issue that completely stops a team from progressing on a work item until it is resolved; it is an impediment that must be removed before work can continue.

Key Points

• Fully halts progress on a task, story, or workflow step until cleared.
• Should be made visible quickly, tracked (e.g., impediment log or board), and actively owned for removal.
• Common causes include external dependencies, missing approvals, access issues, broken environments, or critical defects.
• PMI cross-reference: See impediment.

Example

During Sprint 2, the team cannot test a feature because the staging environment certificate has expired. The Scrum Master logs the blocker, escalates to IT security to renew the certificate, and keeps the blocker visible until it is cleared so the team can resume testing.

PMP Example Question

During an iteration, a developer cannot access the database required to complete a user story. What should the Scrum Master do first?

1. Change the Definition of Done to exclude database testing for this sprint.
2. Extend the sprint to allow time for access to be restored.
3. Record the issue as a blocker, make it visible, and facilitate restoring access.
4. Tell the developer to ignore the issue and start an unrelated story.

Correct Answer: C — blocker (an issue that halts progress until resolved)

Explanation: The lack of access stops work on the item, so it is a blocker/impediment that must be made visible and removed. The other choices undermine agile practices.