Here is a helpful 9-minute presentation on the The Inversion Method (although the last minute is not so helpful.)
As explained here, it less a method and more of a mental model or a general approach for problem-solving and decision-making. In a nutshell, it can be summarized as “avoiding stupidity” or “reverse engineering success”. Instead of analyzing what you should do to reach a goal, generate ways of not reaching it, and then avoid those ways in your striving.
For problem-solving and decision-making, it has a great deal of pertinence and utility for project teams, specifically for planning and/or doing risk management.
Invented by the mathematician Carl Jacobi in the 19th century, it owes much of its current notoriety to frequent references to it by Warren Buffet’s business partner, Charlie Munger. Also, it seems a key inspiration for the strategic planning technique called “Kill the Company”, “Kill Your Company”, or the like, featured in workshops by a number of general business consulting firms.