The sales of the automotive was increased by 3.6% in 2018, sparking the automotive and its spare parts industry for more opportunities. Various strategies have been made to win the competition and increase sales, to expand market share and to reduce production costs. Tire industry as automotive parts industry in Indonesia has faced with tremendous competition and the industry needs an appropriate strategy to reduce production costs by reducing defective products. The building process is workstation of the tire industry with the focus on decline on the defective products. Internal data shows the defective products in the building process of 0.20% in 2017 and 0.17% in July ~ September 2018 which were higher than the company's schedule of 0.12% of total production. The NGT, Shainin system and DMAIC (Six sigma) methods are expected to improve defective products of building process. Based on Pareto diagrams it is clear that there were six defective products causing high defective products. However, with the limited research, BLP defective products with the highest defective product (48%) was used as a pilot project in this study. The preliminary results indicate that the proposed method of this paper could succeed in improving the baseline performance of the building process (sigma level) from 4.48 to 5.02 sigma and could reduce the cost from IDR.1.427.500.00 to IDR. 161.000.000 or 88.69%.