Authors : Arif Bunyamin; Dr. Antonius Setyadi

Volume/Issue : Volume 10 - 2025, Issue 7 - July

Google Scholar : https://tinyurl.com/2hcr4758

Scribd : https://tinyurl.com/4d42ed3f

DOI : https://doi.org/10.38124/ijisrt/25jul961

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Abstract : This research analyzes the delay in coal transportation cycle time from SWA Block to ROM Aster at PT XYZ using the Six Sigma DMAIC approach. The average actual cycle time reached 6.46 hours, compared to the planned 3.62 hours. This deviation was caused by a combination of factors: human (lack of supervision and driver training), machine (availability below 90% and frequent tire issues), method (slow loading and queue delays), material (unavailable coal stock), and environment (non-AWR roads and narrow slopes). The research method involved observation, in-depth interviews, and document analysis. Root cause analysis was conducted using a Fishbone Diagram and NVivo qualitative tools. The DMAIC model was applied to define, measure, analyze, improve, and control the process. Improvements proposed include widening roads, increasing night-shift supervision, training drivers, and integrating stock monitoring systems. The findings highlight systemic operational inefficiencies and offer structured corrective actions for sustainable hauling performance.

Keywords : Cycle Time; Coal Hauling; Fishbone Diagram; Six Sigma; DMAIC.

References :

1. Cahyati, NF, Santosa, B., and Widodo, W., "Fishbone diagram-based root cause analysis," Journal of Industrial Engineering and Management (JIEM), vol. 17, no. 1, pp. 101–110, 2024.
2. Trubetskaya, O., Ivanov, D., and Pavlov, A., “Lean Six Sigma DMAIC in maintenance,” International Journal of Production Economics (IJPE), vol. 255, p. 108789, 2023.
3. Wiguna, W., “Six Sigma for improving production quality,” Jurnal Teknik Industri (JTI), vol. 24, no. 2, pp. 87–96, 2022.
4. Yuniar, DR, Saputra, AT, and Hakim, R., "Eco-driving behavior in mining logistics," Sustainable Operations Journal, vol. 8, no. 3, pp. 45–55, 2020.
5. Himawan, A., Firmansyah, B., and Setiawan, R., “Cycle time variability in open pit mining transportation systems,” Journal of Mineral Technology, vol. 12, no. 2, pp. 23–30, 2020.
6. Scholz-Reiter, B., Freitag, M., and Heger, J., “Performance analysis of mining transportation cycle time,” Production Engineering, vol. 5, no. 4, pp. 345–353, 2011.
7. Wirtz, J., Essentials of Service Management, 1st ed., World Scientific, 2017.
8. Trubetskaya, O., Ivanov, D., and Pavlov, A., “Lean Six Sigma DMAIC in maintenance,” International Journal of Production Economics, vol. 255, p. 108789, 2023.
9. Yuniar, D. R., Saputra, A. T., and Hakim, R., “Eco-driving behaviour in mining logistics,” Sustainable Operations Journal, vol. 8, no. 3, pp. 45–55, 2020.
10. Scholz-Reiter, B., Freitag, M., and Heger, J., “Performance analysis of mining transportation cycle time,” Production Engineering, vol. 5, no. 4, pp. 345–353, 2011.
11. Setiawan, D., Firmansyah, R., and Nugraha, A., “Analysis of hauling performance between working shifts in open-pit coal mines,” International Journal of Innovative Science and Research Technology (IJISRT), vol. 8, no. 2, pp. 45–51, 2023.
12. Pratama, I. G. and Yuliani, R., “Effect of night shift limitations on production throughput in coal transportation,” IJISRT, vol. 7, no. 11, pp. 1024–1031, 2022.
13. Nugroho, S., Maulana, H., and Hidayat, B., “Impact of shift scheduling on supply chain delays in mining operations,” IJISRT, vol. 6, no. 5, pp. 607–615, 2021.
14. Hendrawan, M. and Yusuf, A., “Cycle time reduction in mining logistics using Six Sigma methodology,” International Journal of Innovative Science and Research Technology (IJISRT), vol. 6, no. 4, pp. 554–560, 2021.
15. Siregar, D. A., Fauzan, R., and Rizki, T., “Fishbone and DMAIC analysis to improve transportation performance in mining companies,” IJISRT, vol. 7, no. 9, pp. 923–930, 2022.
16. Putra, R. A. and Dewi, N. S., “Application of Six Sigma DMAIC to control production delays in coal delivery,” IJISRT, vol. 8, no. 1, pp. 188–194, 2023.