Quality Control of the Steel Wire Rod Product by Integration Lean Six Sigma and Taguchi Method

Abstract

RMW Inc. is the global company in Indonesia. One of its product is the steel wire rod. This research aims to control the production process and improve the product quality. This research is using the integration between lean six sigma and taguchi method. The first step is to reduce the waste using lean six sigma method while the second step is to reduce the defect using taguchi method. Based on the identification of seven waste, the most dominant waste is the defect that is caused by there is no setting of the roll entry guide. The product has 11 CTQ (critical to quality) with the focus on laps defect, underfill defect, and overfill defect. Then, the cause of failure is identified using FMEA (failure mode effect analysis). The level of sigma capability is achieved at 4.54 with DPMO (defect per million opportunities) is 4006.55. The first improvement can reduce the time until 8.9 minutes. The second improvement sets the roll entry guide. The optimum factors for setting of the roll entry guide is A factor with 150 tonnages of wear level, C factor by 5 bar of cooling and D factor by 6 ml of lubrication.