<p>The economic production quantity (EPQ) model with a constant production rate is illustrated in the current article. This methodology looks at Pareto-type declined products that provide partial backlogs for interested buyers. Demand is considered a quadratic function of the variable time of decisions. Since industry organisations always want to slow the rate of decline to increase overall profit, it is advantageous to spend money on preservation technologies in this process. Because of this, it is believed that investment in preservation technology is inversely related to the depreciation rate. Also, the inventory control system takes inflation into account significantly. As a result, our model takes inflation into the narrative. As businesses frequently struggle with how much to create and for how long, our paper determines the ideal cycle length, inflation rate, the selling price of goods, and investment in preservative technology, which we predict to enhance the total profit. In addition to considering inflation and shortages, they may set up manufacturing and reproduction to customers’ demands. In the situation of stock exhaustion and depletion, they can reduce holding expenses and losses. This study also provides a numerical example and sensitivity analysis. Total profit maximisation is indicated using MATLAB to approximate concavity around variables.</p>