The basic EPQ models with non-instantaneous deteriorating items: modelling and optimal policy

This paper presents a mathematical framework for analysing the Economic Production Quantity (EPQ) model for items with non-instantaneous deterioration. The non-instantaneous nature of deterioration introduces complexities that are not present in the classical EPQ model with deterioration. This framework allows for a deeper exploration of the model's properties and enables a comprehensive investigation of optimal inventory levels, both with and without full backlogging. By identifying the stationary point of the objective function representing total inventory costs per unit time, a unique optimal inventory policy can be determined. Numerical examples are provided to illustrate the findings.