During PI (Program Increment) planning, the Agile teams own the planning of stories into iterations
While product management, system architects, and the Scrum Master may provide guidance and support during the PI planning process, it is ultimately the responsibility of the Agile teams to plan and prioritize the stories into iterations based on the team's capacity and the program's goals. The Agile teams should work collaboratively to identify dependencies, risks, and opportunities, and to ensure that the plan is realistic and achievable