Quality Control of Metal Electrical Boxes using Model-based Control Charts

Nowadays, electrical boxes are widely used to hold wires and connections in the electric power industry. A group of these electrical boxes are metal boxes that may be exposed to rusting over time. Therefore, quality control and reliability monitoring in the production of these boxes have become an important challenge that should be fully considered. Many approaches have been proposed by researchers to control the quality characteristics and monitor the reliability of products. In this paper, in order to monitor the rusting time of metal electrical boxes, which are subject to interval censoring, some approaches based on model-based control charts are proposed. Subsequently, the performance of the monitoring schemes are compared with respect to the four indices of average run length, extra quadratic loss, performance comparison, and relative average run length. The results reveal that the proposed cumulative sum control chart performs better than the competing control chart. Finally, in order to confirm the effectiveness of the proposed control chart, a case study in the production of metal electrical boxes is addressed.