In this paper we further extend Chen and Wang's study concerning a CSP-1 pl
an applied to the economic manufacturing quantity (EMQ) model with imperfec
t quality. Adopting the backorder assumption for shortages, the modified to
tal inventory cost includes the setup cost, the holding cost, the backorder
ing cost, the inspection cost, and the internal and external failure cost.
By solving the modified EMQ model, we not only obtain the required level of
product quality but also determine the minimum of the total inventory cost