I don't think it's necessarily wrong to use 5-Why's in one's analysis. I am suggesting that it should not be the only tool one uses. If success requires several

I don't think it's necessarily wrong to use 5-Why's in one's analysis. I am suggesting that it should not be the only tool one uses. If success requires several contributing factors that are necessary and jointly sufficient to enable it, then failure should not be limited to a single root cause.