Economic order quantity model with backorder for imperfect quality items

In the classical inventory models, the issue of quality is ignored. However, in a real production environment, it can be observed that there are defective items being produced. These defective items must be rejected, repaired, reworked, or, if they have reached the customer, refunded, and hence, extra costs are incurred. Recently some of researchers explicitly elaborate on the significant relationship between quality imperfection and lot size. In the recent models although quality entered into the models but none of them have considered shortage problem. This paper extends the traditional EPQ/EOQ model by accounting for imperfect quality items when using the backorder EPQ/EOQ formulae. Finally, numerical example is provided to illustrate the solution procedure and concluding remarks are given.