Research On Optimal Inventory Control Strategy For Dynamic Supply Chain Systems

The feedforward and feedback optimal tracking inventory con-trol strategy for two-level supply chain system with demand disturbance, approximate optimal inventory control strategy and approximate optimal tracking inventory control strategy for multi-stage supply chains with lead time are studied in this paper. Details are as follows:1. For the problem of bullwhip effect in two-level supply chain systems resulting from demand disturbance of market, an optimal tracking inven-tory control scheme with feedforward compensation is proposed. First of all, for a case of demand disturbance which is modeled as a linear exoge-nous system, an asymptotically stable desired system is introduced, then an optimal tracking control scheme with feedforward compensation for a supply chain system with demand disturbance is developed based on the linear quadratic performance index. The optimal tracking controller can be obtained by solving a Riccati equation and a Stein equation, respectively. It is found through simulation results that the proposed optimal tracking control scheme is effective to reject the effect of demand disturbance on the supply chain system. Moreover, the control scheme is better than the classical optimal tracking control scheme.2. The approximate optimal inventory control problem of multi-stage supply chains with lead time is studied. By introducing a sensitivity pa-rameter, the original optimal problem is transformed into a sequence of two-point boundary value problems without time-delay term. Then the u-niqueness and the existence of the optimal control law is presented, the optimal controller can be obtained by solving a Riccati equation. Then by using a finite sum of the series, a suboptimal inventory replenishment strat-egy of supply chain system is proposed. Simulation examples show that the inventory replenishment strategy is effective to reduce bullwhip effect and thereby improve the performance of the supply chain system.3. The approximate optimal tracking inventory control problem of multi-stage supply chains with lead time is studied. A approximate op-timal tracking control scheme is proposed such that the controlled output of supply chain system is capable of tracking an introduced asymptotically stable system. The optimal tracking controller could be obtained by solv-ing a Riccati equation and a Stein equation, respectively. Then by using a finite sum of the series, a suboptimal inventory tracking replenishment s-trategy of the supply chain system is proposed. Simulation examples show that this approximate algorithm is effective to restrain the influence of the lead time on the supply chain system.