Enhancing quality in plastic manufacturing: Six sigma application to polybox containers

Authors

  • Nadia Nabila Priyanti Department of Industrial Engineering, Faculty of Industrial Technology, Universitas Trisakti, Jl. Kyai Tapa No. 1, Grogol, Jakarta, Indonesia
  • Johnson Saragih Department of Industrial Engineering, Faculty of Industrial Technology, Universitas Trisakti, Jl. Kyai Tapa No. 1, Grogol, Jakarta, Indonesia
  • Idriwal Mayusda Department of Industrial Engineering, Faculty of Industrial Technology, Universitas Trisakti, Jl. Kyai Tapa No. 1, Grogol, Jakarta, Indonesia

DOI:

https://doi.org/10.31315/opsi.v18i2.12576

Keywords:

Six sigma , DMAIC , Pareto chart , FMEA

Abstract

Historical production data from November 2021 to February 2022 revealed that polybox plastic containers suffered from a 2.84% defect rate, exceeding the company’s 2% threshold. This study applies the Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) methodology to enhance product quality. The Define phase utilized SIPOC and Critical to Quality (CTQ) diagrams to outline quality characteristics. In the Measure phase, P and U Control Charts established a baseline performance with a Defect Per Million Opportunities (DPMO) of 8,420 and a sigma level of 3.89. The Analyze phase employed Fishbone diagrams and Failure Mode and Effects Analysis (FMEA) to isolate root causes. High Risk Priority Numbers (RPN) highlighted worker carelessness (294), welding inaccuracies (252), and manual handling issues (210). Consequently, the Improve phase implemented new Standard Operating Procedures (SOPs), welding guidelines, and hand-truck trolleys. Post-implementation monitoring during the Control phase showed immediate improvements: the DPMO dropped to 6,305, and the sigma level increased to 3.99. These findings confirm the efficacy of Six Sigma interventions in reducing manufacturing defects and aligning production with quality standards.

References

[1] A. Alsulami, F. Albishri, R. Almehmadi, S. Alahmadi, J. Albarakati, and S. Elhag, “Six Sigma-DMAIC to Improve the Quality of Food Service: KAU Case Study,” in Intelligent Sustainable Systems, A. K. Nagar, D. S. Jat, D. K. Mishra, and A. Joshi, Eds., Singapore: Springer Nature Singapore, 2024, pp. 91–101.

[2] N. Kawabata and M. Nin, “Effect of Continual Quality Improvement of Palliative Care Consultation Teams by Iterative, Customer Satisfaction Survey-Driven Evaluation,” BMC Palliat Care, vol. 20, no. 1, p. 46, 2021, doi: 10.1186/s12904-021-00741-2.

[3] C. L. Sim, F. Chuah, K. Y. Sin, and Y. J. Lim, “The Moderating Role of Lean Six Sigma Practices on Quality Management Practices and Quality Performance in Medical Device Manufacturing Industry,” The TQM Journal, vol. 36, no. 5, pp. 1273–1299, Jan. 2024, doi: 10.1108/TQM-11-2021-0342.

[4] N. Fathiya, W. Kurniawan, and I. Mayusda, “Improving the Packaging Quality of Surgical Suture Products at PT. XYZ with the Application of the Six Sigma Method and Failure Mode Effect Analysis (FMEA),” in E3S Web of Conferences, EDP Sciences, Mar. 2024. doi: 10.1051/e3sconf/202450003022.

[5] A. L. Setyabudhi, Sanusi, and I. Sipahutar, “Application of Six Sigma Methodology to Improve the Product Quality of Moldings Plastic (Case Study: PT Mega Technology Batam),” in IOP Conference Series: Materials Science and Engineering, Institute of Physics Publishing, Jul. 2019. doi: 10.1088/1757-899X/505/1/012067.

[6] R. Fitriana, J. Saragih, and D. P. Larasati, “Production quality improvement of Yamalube Bottle with Six Sigma, FMEA, and Data Mining in PT. B,” in IOP Conference Series: Materials Science and Engineering, Institute of Physics Publishing, May 2020. doi: 10.1088/1757-899X/847/1/012011.

[7] H. F. Tamher, J. Saragih, and A. N. Habyba, “Quality Improvement on Pipe Production Using Six Sigma and Data Mining in PT. FIP,” AIP Conf Proc, vol. 2485, no. 1, p. 120001, Aug. 2023, doi: 10.1063/5.0104997.

[8] R. Fitriana, J. Saragih, and S. D. Fauziyah, “Quality improvement on Common Rail Type-1 Product using Six Sigma Method and Data Mining on Forging Line in PT. ABC,” in IOP Conference Series: Materials Science and Engineering, Institute of Physics Publishing, May 2020. doi: 10.1088/1757-899X/847/1/012038.

[9] A. Ishak, K. Siregar, Asfriyati, and H. Naibaho, “Quality Control with Six Sigma DMAIC and Grey Failure Mode Effect Anaysis (FMEA): A Review,” in IOP Conference Series: Materials Science and Engineering, Institute of Physics Publishing, Jul. 2019. doi: 10.1088/1757-899X/505/1/012057.

[10] R. D. Suharno and T. Y. M. Zagloel, “Quality Improvement of Lamination Process Results in The Packaging Industry by Using the Six Sigma Method,” in ACM International Conference Proceeding Series, Association for Computing Machinery, Sep. 2019, pp. 243–247. doi: 10.1145/3364335.3364372.

[11] M. S. Kirkire and G. Abhyankar, “Medical Product Manufacturing Process Capability Improvement Using Six Sigma–DMAIC Methodology,” in Advances in Industrial and Production Engineering, R. K. Phanden, R. Kumar, P. M. Pandey, and A. Chakraborty, Eds., Singapore: Springer Nature Singapore, 2023, pp. 215–230.

[12] S. Saryanto, H. H. Purba, and A. Trimarjoko, “Improve Quality Remanufacturing Welding and Machining Process in Indonesia Using Six Sigma Methods,” Journal Europeen des Systemes Automatises, vol. 53, no. 3, pp. 377–384, Jun. 2020, doi: 10.18280/jesa.530308.

[13] C. M. Yu, T. H. Huang, K. S. Chen, and T. Y. Huang, “Construct Six Sigma DMAIC Improvement Model for Manufacturing Process Quality of Multi-Characteristic Products,” Mathematics, vol. 10, no. 5, Mar. 2022, doi: 10.3390/math10050814.

[14] R. K. Wassan, Z. H. Hulio, M. A. Gopang, U. Sarwar, A. Akbar, and S. Kaka, “Practical Application of Six Sigma Methodology to Reduce Defects in a Pakistani Manufacturing Company,” Journal of Applied Engineering Science, vol. 20, no. 2, pp. 552–561, 2022, doi: 10.5937/jaes0-34558.

[15] F. Pakdil, “Control Charts,” in Six Sigma for Students: A Problem-Solving Methodology, F. Pakdil, Ed., Cham: Springer International Publishing, 2020, pp. 333–373. doi: 10.1007/978-3-030-40709-4_9.

[16] H. Shah, S. Karkera, and S. Vaity, “Waste Reduction of Molded Plastic Parts by Applying Principles of Six Sigma,” in Proceedings of International Conference on Intelligent Manufacturing and Automation, H. Vasudevan, V. K. N. Kottur, and A. A. Raina, Eds., Singapore: Springer Nature Singapore, 2023, pp. 157–169.

[17] R. Nurdyanto and Harwati, “Quality Enhancement in SMEs Through Six Sigma Analysis,” in 2024 ASU International Conference in Emerging Technologies for Sustainability and Intelligent Systems (ICETSIS), 2024, pp. 1517–1521. doi: 10.1109/ICETSIS61505.2024.10459553.

[18] H. Supriyanto, M. L. Reyfasha, and M. F. R. Supriyanto, “Increasing the Sigma Level and Customer Value in the Manufacturing Industry: A Case Study of Cover Components,” International Journal of Mechanical Engineering and Robotics Research, vol. 13, no. 1, pp. 26–34, 2024, doi: 10.18178/ijmerr.13.1.26-34.

[19] E. Xhafka, E. Avrami, G. Canton, and A. Mazreku, “Applying the Ishikawa Diagram and Pareto Chart for Defect Reduction in the Manufacturing Industry. A Case Study from a Textile-Producing Company,” in Proceedings of the Joint International Conference: 10th Textile Conference and 4th Conference on Engineering and Entrepreneurship, G. Guxho, T. Kosova Spahiu, V. Prifti, A. Gjeta, E. Xhafka, and A. Sulejmani, Eds., Cham: Springer Nature Switzerland, 2024, pp. 45–55.

[20] A. Maged, S. Haridy, S. Kaytbay, and N. Bhuiyan, “Continuous Improvement of Injection Moulding Using Six Sigma: Case Study,” International Journal of Industrial and Systems Engineering, vol. 32, no. 2, pp. 243–266, Jan. 2019, doi: 10.1504/IJISE.2019.100165.

[21] M. Gomathi Prabha, T. Rajamohan, S. Manikandan, and S. R. Petluru, “Lead Time Reduction and Quality Improvement in a Manufacturing Industry Using DMAIC Methodology—A Case Study,” in Advances in Forming, Machining and Automation, U. S. Dixit, M. Kanthababu, A. Ramesh Babu, and S. Udhayakumar, Eds., Singapore: Springer Nature Singapore, 2023, pp. 581–599.

[22] I. Mayusda, “Quality Improvement of Tin Ingot Product Using Six Sigma Method at PT Timah Tbk,” OPSI, vol. 16, no. 1, p. 121, Jun. 2023, doi: 10.31315/opsi.v16i1.7434.

[23] T. C. Tyas and I. Giyanti, “Quality control of garment product using DMAIC Six Sigma,” OPSI, vol. 17, no. 1, p. 234, Jun. 2024, doi: 10.31315/opsi.v17i1.7107.

[24] D. A. Purnama, A. Alfiqra, and W. N. Cahyo, “A machine learning-driven Six Sigma framework for enhancing the quality improvement and productivity in the Aircraft Manufacturing,” OPSI, vol. 18, no. 1, pp. 136–151, Jun. 2025, doi: 10.31315/opsi.v18i1.13960.

[25] L. Fitria, D. Tauhida, and A. Sokhibi, “Quality Control with Six Sigma Method to Minimize Polyester Fabric Product Defects at PT Sukuntex,” OPSI, vol. 16, no. 1, p. 110, Jun. 2023, doi: 10.31315/opsi.v16i1.6786.

[26] E. Nursubiyantoro and D. A. Setiawan, “Application Of Six Sigma For Product Quality Control,” OPSI, vol. 11, no. 1, pp. 78–84, Jun. 2018.

[27] Y. T. Jou, R. M. Silitonga, M. C. Lin, R. Sukwadi, and J. Rivaldo, “Application of Six Sigma Methodology in an Automotive Manufacturing Company: A Case Study,” Sustainability (Switzerland), vol. 14, no. 21, Nov. 2022, doi: 10.3390/su142114497.

[28] N. Nandakumar, P. G. Saleeshya, and P. Harikumar, “Bottleneck Identification And Process Improvement By Lean Six Sigma DMAIC Methodology,” Mater Today Proc, vol. 24, pp. 1217–1224, 2020, doi: https://doi.org/10.1016/j.matpr.2020.04.436.

[29] A. William, Ahmad, and L. Laricha, “Improvement of the quality of packed drinking water products using six sigma and kaizen method,” AIP Conf Proc, vol. 2680, no. 1, p. 020204, Dec. 2023, doi: 10.1063/5.0126943.

[30] T. Chuenyindee and Y. T. Prasetyo, “Roller Chains Quality Enhancement using Six Sigma and Failure Mode and Effects Analysis (FMEA),” in ACM International Conference Proceeding Series, Association for Computing Machinery, Apr. 2020, pp. 219–224. doi: 10.1145/3396743.3396780.

[31] Y. D. R. Montororing, M. Widyantoro, and A. Muhazir, “Production process improvements to minimize product defects using DMAIC six sigma statistical tool and FMEA at PT KAEF,” in Journal of Physics: Conference Series, IOP Publishing Ltd, Jan. 2022. doi: 10.1088/1742-6596/2157/1/012032.

[32] Â. Y. Orbak, “Implementation of Design for Six Sigma Methodology on the Car Bumper Production Process,” International Journal of Vehicle Design, vol. 85, no. 1, pp. 69–96, Jan. 2021, doi: 10.1504/IJVD.2021.117162.

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Published

2025-12-30

Issue

Vol. 18 No. 2 (2025): OPSI - December 2025

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Article

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