During which PI Planning activity do Business Owners assign business value to PI Objectives?

During the draft plan review, the teams present their draft PI objectives and plans to the other teams and the Business Owners. The Business Owners then assign a business value to each PI objective, based on the conversation with the team and the alignment with the vision and goals. The business value is a number between 1 (lowest) and 10 (highest) that reflects the relative importance and expected benefit of the objective. The business value is used to measure the ART’s predictability and performance at the end of the PI. References: PI Objectives, PI Planning, Your Guide to Writing Great Iteration and PI Objectives