Wijanarko, W. 2024. Improvement of Mro Material Procurement Efficiency Through the Six Sigma Concept at PT Krakatau Steel (Persero) TBK. Jurnal Indonesia Sosial Teknologi. 5, 10 (Oct. 2024), 4580–4592. DOI:https://doi.org/10.59141/jist.v5i10.5307.