Retrospective is an important ceremony required to complete the PDCA loop, however it is often ignored and does not deliver value.
Scrum Masters have struggled to implement effective retro sessions within their teams, and this problem is compunded which Scrum Scales. In a scaled (or multi team) situation, it is imperative to be able to aggregate retro feedback from teams, into a broader, organization wide improvement plan.
Outline/structure of the Session
The session woudl initially focus on giving a "measurable structure" to the retro witin a sprint team, for continuous tracking, followed by methods to aggregate the results from multiple retro into a summarised action plan.
Effective retrospection and followup on previous action items.
Scrum Masters, Team members, Leaders