An EOQ model for deteriorating items analyzing retailer’s optimal strategy under trade credit and return policy with nonlinear demand and resalable returns

This paper presents an EOQ model where demand is dependent upon time and selling price. In the proposed model of inventory, the retailer allows its unsatisfied customers to return their product whereas the manufacturer offers a full trade credit policy to the retailer. To make our model realistic, we have assumed that the product returned can be resold with the same selling price. Number of returns is a function of demand. In this proposed inventory model considering deterioration, the retailer does not fully reimburse its customers for the returned product. The primary purpose of this inventory model is to determine the optimal selling price, optimal order quantity, and optimal replenishment cycle length in order to maximize the retailer’s total profit earned per unit time. A numerical example is also presented and a sensitivity analysis is carried to highlight the findings of the suggested inventory model.

On the shortage control in a continuous review (Q, r) inventory policy using αL service-level

Popular measures of product availability in inventory systems seek to control different aspects of stock shortages. However, none of them simultaneously control all aspects of shortages, because stock shortages in inventory systems are complex random events. This paper analyzes the performance of αL service measure, defined as the probability that stockouts do not occur during a replenishment cycle, to cover different aspects of stock shortages when used to design an optimal continuous review (Q, r) policy. We show that explicitly controlling the frequency of replenishment cycle stockouts, using the αL service-level, allows to implicitly control the size of the stockouts at an arbitrary time, the size of accumulated backorders at an arbitrary time, and the duration of the replenishment cycle stockouts. However, the cost of controlling the frequency of replenishment cycle stockouts is greater than the cost of controlling the size of stockouts and the duration of the replenishment cycle stockouts.

Joint Pricing and Inventory Model for Deteriorating Items with Maximum Lifetime and Controllable Carbon Emissions under Permissible Delay in Payments

Reducing carbon emissions plays a significant role in developing sustainable inventory systems. In a seller-buyer relationship, an allowable delay in payment is considered for the buyer to manage the stock and simulate the demand. Deteriorating items that usually have specific maximum lifetimes have become a challenge for most firms. Contrary to the importance of these issues, very little research has studied the impact of carbon emissions on deteriorating inventory systems. This paper provides a price-dependent demand for perishable items when carbon cap-and-trade regulation fills the mentioned gap. This model provides a carbon reduction investment scheme and illustrates this investment’s effect on the inventory system. This paper determines the optimal replenishment cycle and selling price, in which: (a) perishable items have specific maximum lifetimes, (b) a specific period of delay in payment is allowed for the buyer to accumulate revenue, (c) carbon is emitted due to ordering and storage operations and carbon cap and trade is regulated along with allowable carbon reduction investment. After developing the model, optimal values are obtained from necessary and sufficient conditions of optimality. Numerical experiments are proposed to validate the model. By developing an algorithm, the optimal values of replenishment cycle, selling price, and carbon reduction technology investment are obtained, and the impact of carbon emissions and efforts to control emissions are outlined. Finally, some managerial applications are mentioned, and future research directions are exposed.

Inventory management with online payment and preorder discounts

PurposeThe advancement of technology opens many opportunities for retailing businesses to increase their profit through innovative strategies, such as discount offers, preorder programs and online payment services. The purpose of this study is to investigate decision-making methods for retailers who sell deteriorating products that utilize an e-commerce platform and offering preorder.Design/methodology/approachThe authors study the optimum price and replenishment cycle when multiple discounts policy is implemented for customers when they purchase during the preorder period and make the payment via an online system. The proposed economic order quantity model works for noninstantaneous deteriorating items that will maximize the total profit. Moreover, it considers the effect of selling price and advertisement on customer demand. The concavity of the profit function is proved. Then, a comparison is carried out between the traditional payment system and online payment. Finally, two numerical examples and the sensitivity analysis are performed.FindingsThe results show the benefit of the system with online payment compared to the traditional one. Further analysis shows that the total profit increases when the frequency of advertisement, interest from the banking company, location perimeter and the nondeterioration time increase.Originality/valueThe proposed model guides e-commerce retailers optimizing the price and inventory decision when they offer a discount, preorder program and online payment service. No researcher has undergone a study with this complexity.