A team I work with shared this with me, I wanted to share it with others in case interesting. 

The team reviews their Flow Metrics in their Sprint Retro. They noticed that their Flow Efficiency had decreased. 

They opened the bottleneck finder for this time period and saw that the wait states "verification" and "stalled" had the highest State Duration Index (SDI), which is not typical for them.

They could prove this was not typical for them by picking a time period over the past several weeks and looking at the bottleneck finder. Typically their active state “In Progress” had the highest SDI. Something had changed to drive up the delay in Verification over the past sprint. 

They formed an experiment to see if they could decrease the time spent in verification. Their hypothesis was that by decreasing the wait time in Verification, this would increase their Flow Efficiency. Stay tuned to hear how their experiment turns out!