The 1st "YHI National QC Team Achievement Contest" concluded in Guiyang, Guizhou Province. Through five days of intense competition, Reducing the Rejection Rate of A3100 Cylinder Covers, a research subject of the "QC-transcending group" of the cold machining plant representing Yuchai Machinery Co., Ltd. stood out of 193 others to claim the title and glorify Yuchai.

In early 2010, the group determined Reducing the Rejection Rate of A3100 Cylinder Covers as the subject of the year. Led by the leader Ren Yongjie and quality engineer Huang Yupeng, the group members made innovation, and, for the first time, used Six-Sigma methods such as "hypothesis testing", "regression fitting analysis" and "scatter diagram" in cause identification and countermeasure implementation. Based on the methods, the group achieved a great success.

In the contest, applications of new methods became highlights and were praised by judges. After the launch of QC findings, expert judges summarized the contest, noting the key to the success of a QC subject is whether its actuality analysis is thorough and proper, whether problem cruxes can be found and whether statistical analysis methods can be used skillfully to solve problems. Judges commented on the statistical analysis methods used in Reducing the Rejection Rate of A3100 Cylinder Covers at the stages of actuality investigation and countermeasure implementation. "The group could find new statistical methods to better solve practical problems, the spirit of breaking away from traditional thinking patterns and making innovation is commendable," judges spoke highly of the group. Also, members of the group shared the tools and methods of the outstanding findings and the method of making the PPT. 

(Ren Yongjie)