Abstract: The financing structure is the composition and proportional relationship of accommodating various capital economic entities. A reasonable financing structure is beneficial to optimize the resource allocation, improve the property right structure, and increase revenue. In the current inventory management model among companies, numerous papers study the effects of delay payment on the reduction in inventory cost, the improvement of inventory strategies and the inventory coordination, which ignore the internal relation between the financing structure and retailer's ordering strategies. In this paper, a simple two-echelon supply chain is studied, making up of one supplier-and-one retailer, and the delay payment, capital constrained and the financing structure factors are integrated into the traditional news-vendor model. After that, an optimal ordering model is established for retailers in the face of random demand, and the optimization theory and method are used to obtain the optimal order quantity and optimal profit of the retailer. Further, the impact of price-cost ratio, purchase cost, repurchase price, inventory cost, shortage cost, ordering cycle, financing interest rate and investment interest rate are theoretically analyzed on the optimal order quantity. Finally, the model is deeply analyzed with the numerical example, and it is found that the numerical results are consistent with the theoretical analysis.
The research results show that the factors such as inventory cost, purchase price, and price-cost ratio are negatively correlated with the optimal order quantity of the retailer,and there is a positive correlation between factors such as repurchase price, shortage cost and the retailer's optimal order quantity; When the selling price is fixed, the repurchase price has the greatest influence on the order quantity. When the ratio of debt financing is constant, the proportion of the price cost will have greater influence. Debt financing ratio, sales price and order cycle are closely related to the market demand distribution function. In this numerical example, the optimal order quantity of the retailer decreases as the proportion of debt financing increases, the optimal order quantity increases with the increase of the selling price, the optimal order quantity decreases with the increase of the order period. The relevant research conclusions can enable retailers to determine the optimal order quantity more effectively when faced with random market demand, and achieve the goal of reducing the total cost and increasing corporate profits.

Key words: financing structure, delay payment, ordering strategy, random market demand