Bingo. When we think about the steps intuitively, we tend to gravitate toward the median. "How long does this usually take?" is asking about a median in surpris

Bingo. When we think about the steps intuitively, we tend to gravitate toward the median. "How long does this usually take?" is asking about a median in surprisingly precise terms. Instead we have to understand the distribution, and the mean as well, and add up how long it takes on average, rather than just in the most numerous case. Further, and perhaps more importantly, by understanding each distribution, you have far greater knowledge about what the expected time will be, and where the delays are most probable; and you can begin to start analyzing where those delays might be coming from in the interactions of all the parts of the system. This is straight-up quality talk right out of W. Edwards Deming, and it's how you start to improve how you produce in general. Good stuff.