When is a Pre-PI Planning event necessary?

A Pre-PI Planning event is designed to prepare for the upcoming PI Planning session, particularly in scenarios where multiple Agile Release Trains (ARTs) need to align. This alignment is crucial because it ensures that the various teams understand each other's objectives, dependencies, and constraints, facilitating a cohesive plan that supports the overall mission of the organization.

Through Pre-PI Planning, stakeholders from different ARTs can discuss shared initiatives, priorities, and any cross-team dependencies. This collaboration enhances communication, minimizes misunderstandings, and helps in aligning backlogs across ARTs, ensuring that all teams have a shared understanding of what needs to be accomplished in the upcoming Program Increment.

Other scenarios might slow down or complicate planning, such as having only one day for PI Planning, coordination among Product Owners, or teams struggling with story estimation, but they do not necessitate a Pre-PI Planning event like the need for alignment does.