An Inventory Model for Obsolescence Items with Permissible Delay in Payments and Inflation

In classic inventory control system, the sales revenue is received immediately upon delivery of the products and the products have unlimited lifetime. But, in real world, there are items that lose their value over time because of the emergence of the new technology which are known as obsolescence items. Moreover, the seller can authorize the purchaser to delay the purchase. In this paper, an obsolescence inventory control model with delay in payment policy will be considered in an inflationary context in order to achieve minimum cost and numerical results are also presented in a real case study of the mobile retail industry. The results show according to the considered permissible payment period which is determined based on the actual market situation, with decreasing in the obsolete period, given that the risk of obsolete goods will increase, the optimal order quantity will decrease. In addition, the results indicate that the use of inventory management policies with regard to delayed payment reduces the cost of inventory.