the traditional economic production quantity (epq) model assumes that during the production process no imperfect item is produced. but in the real production system, due to imperfect production process or other factors, imperfect quality items may be produced. furthermore, it is well-known that the total production-inventory costs can be reduced by reworking the imperfect quality items produced...

The traditional economic production quantity (EPQ) model assumes that the production products are all perfect. It is not always true in the real production system, due to imperfect production process or other factors, imperfect quality items may be produced. Furthermore, it is well-known that the total production-inventory costs can be reduced by reworking the imperfect quality items produced w...

The basic assumption in the traditional inventory model is that all outputs are perfect items. However, this assumption is too simplistic in the most real-life situations due to a natural phenomenon in a production process. From this it is deduced that the system produces non-perfects items which can be classified into four groups of perfect, imperfect, reworkable defective and non-reworkable d...

in this model, we establish an inventory model to determine the optimal inventory replenishment scheme for the economic production quantity (epq) model for imperfect, deteriorating items with sales return service under multiple production and rework setup. in one cycle, production process can produces the products in m production setups and reworks the defective items in one rework setup. the c...

In the classical inventory models, the common unrealistic assumption is that all the items produced are of good quality in nature. However, in realistic environment, it can be observed that there may be some defective items in an ordered lot. These items are usually picked up during the screening process and are sold as a single lot at the end of screening process. Further, it is tacitly assume...

A real economic growth only comes from increasing quality and quantity of the factors of production. Most production systems produce items which are of imperfect quality. In a production/inventory situation items which are received or produced are not of perfect quality. Thus the presence of defects which is inevitable in a produced/ordered lot is sorted out by the process of screening. Handlin...

The classical economic production quantity (EPQ) model assumes that items produced are of perfect quality and the production rate is constant. However, production quality depends on the condition of the process. Due to process deterioration or other factors, the production process may shift and produce imperfect quality items. These imperfect quality items sometimes can be reworked and repaired...

In this paper, two economic production quantity (EPQ) models are proposed for deteriorating/imperfect items with rework process. The production process is imperfect, and imperfect quality items are reworked to become serviceable. At the same time, the remaining good quality items may deteriorate. The inspection of deteriorated items is also imperfect, so that deteriorated items may be sold to c...

This paper extends an imperfect production inventory model to machine breakdown at a random time and rework of defective items. Any manufacturing system wants to produce perfect quality items. But in long run production process, there may arise different types of difficulties like labor problem, rawmaterial problems, operator problems, etc., due to that the machinery systems shift from in-contr...