My name is Michael McKlay and I am having trouble in my Operations Management class. I didn't but the textbook so I'm pretty lost; our current unit is Inventory, specifically, inventory control systems. I'm having trouble with the math; I was never very good at stats. The Prof keeps talking about 2 main inventory control systems, the continuous review (Q) system, and the periodic review (P) system. I missed the class on it and am desperately trying to catch up before the next midterm. I'm looking at examples online and its all greek to me. Can you please explain the difference between the two systems, and how I am supposed to calculate the "Reorder Point" (ROP) and "Period of Risk" for both systems?