Abstract:
The purposes of this project were to study and develop the defect reduction in the gravity casting process by using quality activity of Yachiyoda Alloy Wheel Co., Ltd.
The data of defect in the gravity casting process were collected from July to October 2014. it was done by members of quality activity group in which based on the three main truths, real place (Genba), real notice (Genbutsu) and real environment (Genjitsu). It was found that the first problem affecting the defect in the gravity casting was C 31 (pinholes). Thus, the members of the quality activity group have developed defect reduction process to solve the problem by 1) problem identification 2) problem analysis 3) problem adaptation 4) process control 5) result comparison between before and after improvement 6) standard identification after improvement.
The results from implementing this defect reduction process showed that the defect has dropped from 6.48 percent to 2.90 percent. This could be seen as 55.20 percent reducing from original defect rate. The production cost was also declined approximately 781,000 Baht per month. This prospering defect reduction required no addition process and resources.