You take the DeLorean back to the beginning of the project Source:
This activity is great for looking at a longer period of time. Put on your storyteller hat and ask your team to imagine the following scenario:
"You are sitting relaxed at your computer working, when suddenly there is a loud bang and a huge cloud of dust is in your room. You cough and as the dust settles, you realize that a car has driven through the wall of your house. You approach cautiously to see what has happened. The car looks futuristic and has gullwing doors. You wipe the dust off the windshield and realize: it's Marty McFly with his DeLorean. He seems unharmed, but is unconscious. You sense your chance and gently push Marty into the passenger seat. The time machine seems to be undamaged. You risk it and travel back to the beginning of your project: Greenfield. Not a single line of code has been written yet. Now you have the possibility to start again from scratch:
What do you definitely keep?
What do you do differently this time?
What were your biggest learnings?"
Give everybody 7 minutes to write down their ideas on sticky notes – 1 idea per sticky. When the time is up, the first person briefly presents their stickies for the first category and posts them on the board for this category. Then the second person presents and so on. Cluster as you go along. What themes do appear?
Get a sense of everyone's position and reach consensus Source:
When the team can't decide between two options, create a big scale (i.e. a long line) on the floor with masking tape. Mark one end as option A) and the other as option B). Team members position themselves on the scale according to their preference for either option. Now tweak the options until one option has a clear majority.
Create a big scale (i.e. a long line) on the floor with masking tape. Mark one end as 'Great' and the other as 'Bad'. Let participants stand on the scale according to their satisfaction with the retrospective. Ask people what they notice.
Psychologically, taking a stand physically is different from just saying something. It's more 'real'.
See activity #43 on how to begin the retrospective with the same scale.