Fithri, Prima, and Niffy Eri Yeni. 2016. “Analisis Pengendalian Kualitas Pada Engine Boss Drive Face K44F Dengan Metode Six Sigma Di PT. Sparta Guna Sentosa”. Jurnal Optimasi Sistem Industri 15 (2):105-13. https://doi.org/10.25077/josi.v15.n2.p105-113.2016.