When enhancing an existing product, which piece of documentation is LEAST useful for a Scrum Team?

In the context of enhancing an existing product, the full history of retrospective plans and lessons learned is the least useful piece of documentation for a Scrum Team. While retrospectives are crucial for continuous improvement, the documentation from past retrospectives primarily focuses on team dynamics, processes, and specific action items that may not have direct relevance to the current state of the product itself.

The current Product Backlog is essential as it outlines the features, enhancements, and fixes the team needs to prioritize for the product's future. User feedback logs provide invaluable insights from actual users, helping the team understand customer needs and satisfaction regarding the product. Prior sprint review notes capture feedback and decisions made during stakeholder reviews, which can also inform the direction for future enhancements.

In contrast, although the history of retrospective plans and lessons learned can contribute to team performance and process improvements, this documentation doesn't typically contain information directly applicable to product features or enhancements. Thus, it's less useful in guiding the team on how to effectively enhance the product compared to the other documentation types mentioned.