Abstract
It is well known that the fluctuation in stochastic demand often produce the inventory fluctuation which has an effect on service ration and mean stock in an ordering system. The key point of inventory management is a problem how to make the inventory fluctuation as small as possible. H.J.Vassian introduced a reorder rule which minimized it on an assumption, and then the author developed Vassians's model into a fixed-cycle ordering system under proportional control, and tried to analyze the feedback function in the system. The author obtained the conclusion that the inventory fluctuation by the new reorder rule is smaller than that by Vassian's rule.
