premise: The SKUs can be classified into three different classes with varying demands and demand variations . 
hypothesis: We classify the SKUs into three those with high demand ( averaging 5 , 700 units a week ) and low demand variation ( Cv=0.6 ) , those with medium demand ( averaging 3 , 000 units a week ) and medium demand variation ( Cv=0.7 ) , and those with low demand ( averaging 1 , 300 units a week ) and high demand variation ( Cv= 1.3 ) .