Process improvement using Six Sigma DMAIC in the bearing component manufacturing industry: a case study

Bearing parts manufacturing process is highly crucial in maintaining the quality of final product. This paper elaborates the use of the Six Sigma DMAIC approach to minimise variation in dimensions of inner and outer races of ball bearings for enhancing process quality in a manufacturing firm. In various phases of DMAIC, Six Sigma quality improvement tools like voice of customers and employee, statistical process control, control charts, process capability charts, customer/employee survey, and fishbone diagram were used. MINITAB18.0 software was used for data analysis. The results revealed that the adoption of the Six Sigma DMAIC approach significantly improved the process quality. Sigma level was improved from 2.5 to 3.8; defects per million opportunities were reduced from 0.632% to 0.023% and process variation was reduced from ±5 to ±3 and was well within target limits.