مدل مقدار تولید اقتصادی برای موارد رو به وخامت با نصب تولید چندگانه و دوباره کاری

Rework is one of the main issues in reverse logistic and green supply chain, since it can reduce production cost and environmental problem. Many researchers focus on developing rework model, but few of them developed model for deteriorating items. In this paper, we develop an economic production quantity (EPQ) model for deteriorating items with rework. In one cycle, production facility can produce items in m production setups and one rework setup, (m, 1) policy. An example and sensitivity analysis is shown to illustrate the model. The results show that the deteriorating rate affects the optimal cost per unit time, but the effect is not significant. The parameters that significantly affect the optimal total cost per unit time are the serviceable holding cost, the production setup cost and the demand rate.

One competitive advantage in global competition market is producing high quality products. In order to produce high quality products, defective products eliminated through 100% screening. For an economic reason and environmental concerns, defective products are reworked to become serviceable items. Rework process is also one important issue in reverse logistics where used products are reworked to reduce waste and environment problems.

In this paper, we develop an economic production quantity model for deteriorating items with rework process. We assume there are m production setups and one rework setup in each cycle. The sensitivity analysis show that the number of production setup in each cycle increases with increase in the value of the production rate, the rework setup cost and the serviceable inventory cost; it decreases when the value of production setup cost and rework inventory cost increase. The optimal production time is sensitive to changes in the production rate. The optimal total cost is sensitive to the changes in the production setup cost, the serviceable inventory cost and the demand rate. The optimal production cost is not sensitive to changes in the deteriorating rate and the deteriorating cost. The deteriorating rate and the deteriorating cost affect the total cost per unit time, although the changes are not significant. An extension to this paper can be done to consider different production scheme in each cycle. Further research also can be done to consider stochastic demand.