THE EPQ MODEL WITH DETERIORATING ITEMS UNDER TWO LEVELS OF TRADE CREDIT IN A SUPPLY CHAIN SYSTEM

There are two kinds of two levels of trade credit policies addressed by Huang [15] and Teng [29], respectively. Liao [21] presents the EPQ model with deteriorating items under two-level trade credit policy from the viewpoint of Huang H while Chang, Teng and Chern [2] discuss the model from the viewpoint of Teng [29]. However, errors are found in the process of the modeling in Chang et al. [2]. The main purpose of this study is to improve the model of Chang et al. [2] and develop a more general EPQ inventory model. A theorem is also provided for practitioners to make right decisions.