Paseru, A. T., G. Yudoko, D. A. Sanusi, P. Z. Ardiansyah, and A. Limowa. “Performance Optimization of Coal Hauling Operations Through DMAIC Framework: A Case Study at PT Berau Coal”. Journal Integration of Management Studies, vol. 3, no. 2, June 2025, pp. 261-73, doi:10.58229/jims.v3i2.360.