In this study, we applied a conceptual Six Sigma/design of experiment hybrid framework that aims to integrate the Taguchi method and Six Sigma for process improvement in a complex industrial environment. In this context, the Six Sigma methodology was employed on a company operating within the automotive industry to improve a manufacturing process which caused a customer complaint within the company. Studies employing the Taguchi experiment design usually focus on a single variable and neglect the effects of adjustments on remaining quality characteristics. In this study, a multi-response Taguchi design of experiment was preferred, and all of the quality characteristics were taken into account. In our study, define, measure, analysis, improve and control phases were used to reduce the nonconformity rate from 23.940 percent (baseline) to 0.049 percent. As a result of implementing Six Sigma, the sigma level increased from 2.21 (baseline) to 4.80.