A term I came across from Mental Models Vol. 1. But this is something that I have found myself doing and has been useful in helping me make decisions.
When presented with a decision that is a) affected by a lot of uncertainty the future holds b) a large set of possible outcomes can be guessed, then having a theoretical world generator helps.
Having a checklist of aspects to consider is a good idea. A set of checklists covering different dimensions. Maybe they can be classified as internal or intrinsic aspects and external ones. Or can be classified in terms of time.
Thinking about the possibilities in a form of a tree can also help.
After mapping out most of the outcomes and possibilities. The next step is to individually think about the probability of each outcome from happening.
Now here is the kicker. What makes this a really neat is that we have to start thinking about the different outcomes and work our way backwards to the event&decision. Thinking forward and backward through a possibility tree.
This exercise can easily backfire too. So figuring out on what problems this approach works and doesn't is key. This takes a lot of trial and error, increasing domain knowledge and in general being able to ingest a large amount of information before running the TWG.
TWG is a good way to evaluate your past decisions. Given the information that you had at the time and if you run a TWG now for this decision, how would your decision change.
"I rather be roughly right than be precisely wrong". Avoid the craving to go into details of outcomes of trigger that should happen. Keep it as broad as possible. When it comes to figures and statistics, look at ranges and trends not at actual figures down to decimal