ACH (Analysis of Competing Hypotheses) is a piece of open source freeware which was originally developed as part of a CIA project and has now been donated to the world for free download. The program basically allows you to set up a structured decision making process using a sophisticated hypothesis testing structure.

First define your question, then set down the possible hypotheses. Then list the evidence for and against each hypothesis, add them to the matrix and check the inconsistencies. Refine, check, refine until satisfied. It’s all very rigorous and should help you come out with a rational, plausible and perhaps even irrefutable solution? Or not.