The Program will first begin decomposing those Epics into multiple Features. With these Features in hand, the Program team now needs to prioritize all of the Features through the Program Kanban process to evaluate the needed runway for each Feature prior to including it for the PI Planning Event.1
Just as in the Agile Portfolio, there are factors to consider for Prioritization. The first consideration is the business value provided through the Feature. Other important factors to consider include time criticality, risk mitigation or reduction, and the effort required to implement the story. Weighted Shortest Job First (or WSJF2) is a helpful tool to prioritize user stories in an efficient way, which takes all of these factors into consideration.
In addition to the prioritization of the Features, the Program is responsible for prioritizing any Enablers3 that are essential for the Program to deliver these Features to the Team segment. In areas where Architectural or User Experience Runway4 needs to be created, there should be identified Enablers for each area.
For more information on WSJF prioritization within the Scaled Agile Framework®, review the following abstract: