Modeling and Sliding Mode Control of Supply Chains With Limited Product Shelf Life

Recently, much work has been devoted to the management of perishable inventories. However, the available results are obtained under various simplifying assumptions. It is most often assumed that the amount of deteriorating goods is proportional to the total amount of goods stored in the warehouse. Since this assumption is quite unrealistic, in this article we explicitly take into account the fact that every product has a limited shelf life (represented by an expiration date). Therefore we are introducing a non-linear, state space model of supply chains with a finite shelf life. In this model, the remaining shelf lives are represented by individual state variables. In the first place, stored products with the shortest shelf life are sold, and in the event of insufficient demand, the products are disposed of. We then apply a sliding mode control (SMC) strategy to control the flow of goods in the system under consideration. It has been shown that the proposed SM control strategy prevents the loss of products due to the end of their shelf life, and ensures full satisfaction of unpredictable consumer demand. Moreover, the strategy requires limited storage capacity and respects the capabilities of suppliers. These properties are then verified in a simulation example.