Monitoring Welding Process on Ship Construction Using Demerit Control Chart and Fuzzy Analytics Hierarchy Process Integrated Statistical Process Control

Quality monitoring in the welding process of ship construction has been carried out using a rejection ratio. However, this approach is ambiguous and does not provide a clear indication of whether the welding process is under control. Statistical quality control (SQC) is a more effective method of quality monitoring that can provide a more definitive assessment of the welding process. In this paper, we propose a new SQC method for the welding process based on the demerit chart. The demerit chart is a statistical tool that uses a weighted sum of defect sizes to assess the quality of a product. We have developed a new demerit chart that is based on the analytic hierarchy process (AHP), a decision-making method that can be used to assign weights to different factors. We evaluated the performance of our new demerit chart using data from a ship construction project. The results showed that our demerit chart was able to detect welding defects that were not detected by the rejection ratio method. We also found that our demerit chart was more sensitive to changes in the welding process than the rejection ratio method. Our results suggest that the demerit chart is a more effective method of quality control for the welding process than the rejection ratio method. The demerit chart is capable of detecting welding defects that are not detected by the rejection ratio method, and it is more sensitive to changes in the welding process.