The economic order quantity (EOQ) model is the simplest and earliest inventory model in the literature. Its simple mathematics is attributed to its assumptions, which are rarely met. Salameh and Jaber [2000. Economic production quantity model for items with imperfect quality. Int. J. Prod. Econ. 64, 59–64] addressed one of these assumptions that items received or produced are not of perfect qua...

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...

Certain inventory items are living organisms, for example livestock, and are therefore capable of growing during the replenishment cycle. These items often serve as various saleable food items downstream in supply chains. The purpose of this paper is to develop a lot sizing model for growing items if the supplier of the items offers incremental quantity discounts. A mathematical model is derive...

 Imperfect production processes lead to imperfect products and decrease the profit of a business. Improvement in the production process by increasing the investment cost will decrease the defective percentage of items. This study develops an EPQ model with investments on imperfect production processes under limited capital. An algorithm is developed to derive the replenishment and investment p...

a r t i c l e i n f o The optimal replenishment policy for an economic production quantity (EPQ)-based inventory model with nonconforming items and breakdown is presented. A real-life production system inevitably generates nonconforming items and has equipment breakdowns owing to process deterioration or other uncontrollable factors. This study addressed these issues in an EPQ-based system to o...

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 practices, not only production but inspection processes are often not perfect, thereby generating defects and inspection errors. Previous imperfect-quality inventory studies, however, have mostly focused on developing cost-minimizing models that do not consider imperfect inspection processes and related defect sales return issues despite their practical significance. Thus, this study propose...