“After a couple of tries, I end up with a graph that looks like this: I tell them what Erik told me at MRP-8, about how wait times depend upon resource utilization. “The wait time is the ‘percentage of time busy’ divided by the ‘percentage of time idle.’ In other words, if a resource is fifty percent busy, then it’s fifty percent idle. The wait time is fifty percent divided by fifty percent, so one unit of time. Let’s call it one hour. So, on average, our task would wait in the queue for one hour before it gets worked. “On the other hand, if a resource is ninety percent busy, the wait time is ‘ninety percent divided by ten percent’, or nine hours. In”