A hardening sprint in Scrum is an additional sprint added at the end of a development cycle, typically aimed at fixing bugs, addressing technical debt, or stabilizing the product before release. It’s often used when there are concerns about the quality of the product or when there’s a backlog of unresolved issues that couldn’t be addressed within the regular sprint cadence.
However, hardening sprints are considered by some to be an anti-pattern in Scrum for several reasons:
- Deferring Quality: By leaving bug fixes and technical debt until the end of the development cycle, teams risk accumulating a large amount of issues that can be difficult and time-consuming to address. This can lead to a rushed and potentially less effective effort to resolve them during the hardening sprint.
- Breaking the Iterative Flow: Scrum is based on the principles of iterative development, with each sprint delivering a potentially shippable increment of the product. Adding a hardening sprint at the end disrupts this flow and may lead to a lack of focus or urgency during regular sprints, as team members might rely on the hardening sprint to fix issues.
- Hiding Problems: Hardening sprints can sometimes be used as a way to mask underlying issues with the development process or team dynamics. Instead of addressing root causes of poor quality or technical debt as they arise, teams may defer them to the hardening sprint, which can lead to a lack of accountability and improvement.
- Reduced Transparency: Since hardening sprints are often added as an ad-hoc measure to deal with problems, they can reduce transparency into the team’s progress and the actual state of the product. This can make it more difficult for stakeholders to understand the reasons behind delays or quality issues.
Overall, the goal of Scrum is to deliver high-quality increments of the product regularly and consistently, and hardening sprints can undermine this goal by allowing issues to accumulate and by disrupting the iterative flow of development. Instead, Scrum teams are encouraged to focus on maintaining high standards of quality throughout each sprint and to address any issues as they arise, rather than deferring them to the end.