An Order Inventory Model for Delayed Deteriorating Items with Two-Storage Facilities, Time-Varying Demand and Partial Backlogging Rates Under Trade-Credit Policy

The retailer's ideal replenishment strategy for non-instantaneous decaying goods with two-phase demand rates, two storage facilities, and shortages under a permissible payment delay has been determined in this study. While the constant demand rate is considered once deterioration has begun, the demand rate up to that point is believed to be a time-dependent quadratic function. Backlogs and shortages are also taken into consideration. Whether or not the backlog will be accepted depends on how long it will be until the next replenishment. As a result, the backlogging rate fluctuates and depends on how long it takes for the next refill. The models identify the ideal cycle length, order amount, and period at which the inventory level in the owned warehouse reaches zero in order to reduce the overall variable cost per unit of time. For the solutions to exist and be unique, both the necessary and sufficient requirements must be met. The best trade credit period is identified for each model using numerical examples, and the best model among the created models is identified using the best trade credit periods. Sensitivity analysis can offer some managerial insights