The Sprint

Sprints are the heartbeat of Scrum, where ideas are turned into value. They are fixed-length events of one month or less, chosen to create consistency. A new Sprint starts immediately after the conclusion of the previous Sprint. All the work necessary to achieve the Product Goal — Sprint Planning, Daily Scrums, the Sprint Review, the Sprint Retrospective and the development work itself — happens within Sprints. Each event in Scrum is a formal opportunity to inspect and adapt, and the Sprint is the container for them all.

During the Sprint: no changes are made that would endanger the Sprint Goal; quality does not decrease; the Product Backlog is refined as needed; and scope may be clarified and renegotiated with the Product Owner as more is learned. Sprints enable predictability by ensuring inspection and adaptation of progress toward a Product Goal at least every calendar month. When a Sprint's horizon is too long, the Sprint Goal may become invalid, complexity may rise and risk may increase; shorter Sprints generate more learning cycles and limit the cost of a wrong direction to a smaller time frame.

A Sprint could be cancelled if the Sprint Goal becomes obsolete. Only the Product Owner has the authority to cancel the Sprint.

Study focus: there is no "Sprint 0", no "hardening Sprint" and no gap between Sprints in Scrum. Sprint length is not changed mid-Sprint to fit unfinished work, and work that is not Done does not count as part of the Increment.