FARCA -- Fault and Root Cause Analysis -- is what you do when you've got observations and symptoms of outcomes, but no real supporting explanation of the underlying causes and failure modes.
Every PMO admonishes: Don't act on symptoms! Get to the 'facts'. Find out what's causing this
And thus: deductive analysis*. When you've got the answer; now you must discover the question.
Naturally, there is the "five why's" analysis to kick it off: ask why five times in a indentured set of questions. You may indeed get to the root cause.
But, if you really need to do analysis, then here's a methodology training aide in just 71 pages!
*[Of course, there's the corollary, Inductive analysis: You got the question -- what happens if ... -- but you don't have the answer. See: "For want of a nail ..." ]
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