Apply cadence, synchronize with cross-domain planning. —SAFe Lean-Agile Principle #7 Pre- and Post-PI Planning Program Increment (PI) planning is the critical, cadence-based synchronization point for every ART. For Solution Trains, however, there are two additional activities: pre- and post-PI planning. They support and coordinate the various ARTs involved in the Solution Train. Planning at this higher level helps align Solution development as a whole and provides direction and visibility into where the trains are going to the next PI. Details Pre-.