Document Type: Research Paper
Department of Industrial Engineering, Yazd University, Yazd, Iran.
Department of Industrial Engineering, Science and Art University, Yazd, Iran.
Department of Industrial Engineering, University of Bojnord, Bojnord, Iran.
One way to control the quality of products is to inspection the lot inputs. The focus of this paper is on a non-linear integer programming model for determining an optimal single sampling plan for inspecting different parts so that the total cost of the quality control is minimized and we try to improve the quality of inputs to the assembly line by applying a rectifying inspection policy. The optimization model includes the cost of inspection, the cost of non- conforming items entering the assembly line and the cost of rejecting the items. In this research, it is assumed that the inspection is perfect and zero acceptance number policy is employed for inspection. If a non- conforming item is found in the sample, the total lot is rejected. Each part is different in the risk of non- conforming items, the cost of non- conforming items, the size of the lot and the cost of inspection. In the practical example, it can be seen that the rate of defective items, followed by the cost of defective items and the cost of lot rejection, have been greatly reduced following the proposed methods and minimized the cost of quality control.