This work is to study the behavior of certain storage systems in which items with different turnover rates are stored. In particular, we assume that items can be divided into two types: high and low turnover. We try to find simple policies that induce favorable zoning, which will reduce the storage and retrieval distance of items. We define a desirable property of a good policy which we call asymptotically efficient, and show that the Zone-z policy is asymptotically efficient if the zone size is proportional to the expected number of high turnover items in the system in equilibrium.