An integrated statistical analysis for process improvement

The paper deals with the implementation of Six Sigma methodology on manufacturing of shafts used in submergible pump. The paper showcases the study carried out on the grinding machine used in manufacturing process. The manufacturing unit was suffering from poor quality level due to high rejections of submergible pump systems. The initial study on the grinding machine revealed highly significant variance and a low value of process capability index. As robust design is one of the salient modules of Six Sigma Management, appropriate experiments were designed, conducted and analyzed to resolve the said problem. Details of the study carried out are reported in the paper. The end results of the study were confirmed with the manufacturer that the rejection level of the final output i.e. submergible pumps is substantially reduced by realigning the process with the parameters recommended by the analytical study. For further reduction in variance of the process a detailed Gauge R&R was applied. The outcome of the analysis is reported in the paper. © 2012 The Society for Reliability Engineering.