Great question and one that I think many of us wrestle with.
I have seen this work well when teams agree on a clear single focus before entering into ideation. Too often teams try to take on too much and it derails the effort before they even get to ideas for action. So hold them to picking one thing to start with. That doesn’t mean they can’t come back and address other results that need action in the future.
Once that one thing has been picked then the fun begins.
I love using design thinking in these sessions where participants are encouraged to go broad with ideation and the supported to narrow to the best ideas. This is a summary of a process that I have seen work well at our organization and many others. The ideation exercise is particularly useful.
Provide Clear Instructions/Guidance - Keep in mind is that managers are often not comfortable facilitating group activities like this, so giving them clear instructions will be critical.
Allow time for Solo ideation - The power of these ideation exercises comes from the diversity of thought and experience in the room. If you try group ideation without the initial solo ideation, teams may find that they too quickly narrow and follow the loudest voices in the room.