Case study in six sigma methadology: manufacturing quality improvement and guidence for managers

TL;DR: In this paper, the authors discuss the successful implementation of Six Sigma methodology in a high precision and critical process in the manufacture of automotive products, which resulted in a reduction of tolerance-related problems and improved the first pass yield from 85% to 99.4%.

Abstract: This article discusses the successful implementation of Six Sigma methodology in a high precision and critical process in the manufacture of automotive products. The Six Sigma define–measure–analyse–improve–control approach resulted in a reduction of tolerance-related problems and improved the first pass yield from 85% to 99.4%. Data were collected on all possible causes and regression analysis, hypothesis testing, Taguchi methods, classification and regression tree, etc. were used to analyse the data and draw conclusions. Implementation of Six Sigma methodology had a significant financial impact on the profitability of the company. An approximate saving of US$70,000 per annum was reported, which is in addition to the customer-facing benefits of improved quality on returns and sales. The project also had the benefit of allowing the company to learn useful messages that will guide future Six Sigma activities.