Don didn't dismiss anything they raised, even though some of them looked to me like pitiful excuses. With each problem they raised, Don made them quantify the negative impact. Then he guided a discussion of how much of that impact is due to what was already described on his diagram. He kept on referring to it as their current-reality-tree; the logical description of the effects stemming from the fact that they operate in the environment created by the tons-per-hour measurement.
