Introduction .The current investment in inventories in USA is enormous; .It amounted up to $1.57 trillion in the third quarter of 2007; It accounts for 20-25%of the total annual GNP(general net product); .There exists enormous potential for improving the efficiency of economy by scientifically controlling inventories; Farm 11粉 7对 Inventory model $174.6 s1146 billion billion discussed here are most Retail 30% Monufocturing Fig.4-1 (29周 applicable to $472.5 Breakdown of boa 3454.9 billion the Total manufacturing, Wholesale Investment in 239 wholesale,and retail Inventories 353.6 billion in the U.S sectors,composing 82 Economy (2007) Total investment-$1,570.2 billion of the total Survey of Current Business Uuly 2007)Introduction •The current investment in inventories in USA is enormous; •It amounted up to $1.57 trillion in the third quarter of 2007; •It accounts for 20-25% of the total annual GNP (general net product); •There exists enormous potential for improving the efficiency of economy by scientifically controlling inventories; Fig. 4-1 Breakdown of the Total Investment in Inventories in the U.S. Economy (2007) Inventory model discussed here are most applicable to manufacturing, wholesale, and retail sectors, composing 82 % of the total