ABSTRACT
The application of differential equations in the inventory model is unavoidable. Without inventory level calculation, it is impossible to decide for the industry. Generally, most of the products that are use on day-to-day basis are deteriorating items, and each product has a particular expiry date. It is always not possible for the consumer/retailers to pay the whole amount of the product. Thus, to satisfy the customers, a certain delay period is provided to the consumer; in that period, they can pay the amount of the product, and no extra amount will be charged for this delay period. The journey of the inventory model started several years ago. Researchers always try to incorporate different new strategies along with the inventory system so that the industry can optimize the system’s cost or profit. The variable production system is too effective due to demand variability and the deterioration of product production systems.
