Who is responsible for creating a Product Backlog item's estimate?

The responsibility for creating a Product Backlog item's estimate lies with the Development Team. This is because the Development Team is the group that possesses the technical skills and knowledge necessary to assess the complexity and effort required to complete a backlog item. During the Scrum events, particularly during backlog refinement sessions and Sprint Planning, the Development Team discusses and evaluates the items in the Product Backlog, contributing their insights to arrive at a collective estimate.

The Development Team’s estimates are based on their understanding of the work that needs to be done, allowing for more accurate forecasting and planning. The team evaluates various factors such as technical complexities, dependencies, and the skills required to deliver the increase in product functionality.

While the Product Owner may provide context regarding the value and priority of backlog items, it is not their role to create the estimates, as they typically do not possess the same level of technical insight into the work involved. The Scrum Master facilitates the Scrum process and helps to ensure that the team adheres to Scrum principles; however, they do not estimate the backlog items. Stakeholders provide requirements and feedback but are not involved in the estimation process directly.