SAFIRIN, MT. ANALISIS NON VALUE ADDING ACTIVITY DAN DEFECT DENGAN PENDEKATAN LEAN SIX SIGMA DI PT. INDUSTRI KEMASAN SEMEN GRESIK - TUBAN. Matrik : Jurnal Manajemen dan Teknik Industri Produksi, [S. l.], v. 7, n. 2, p. 24–38, 2018. DOI: 10.30587/matrik.v7i2.369. Disponível em: https://journal.umg.ac.id/index.php/matriks/article/view/369. Acesso em: 15 jun. 2025.