Improving Surface Finish Quality of Plastic Molds via VSM and DMAIC Integration

https://doi.org/10.61487/jiste.v3i3.187

Authors

  • Muhammad Kholil Universitas Mercu Buana
  • Syarif Hidayat Universitas Mercu Buana
  • Alfa Firdaus Universitas Mercu Buana

Keywords:

value stream mapping (vsm), six sigma, dmaic, mold making process, surface finish quality

Abstract

The rapid growth of manufacturing demands continuous process improvement. This study examines a plastic manufacturing company’s Mouldshop, which has not met performance targets an average lead time of 52 days (target 50 days) and a 75% success rate (target 93%) and struggles to achieve the desired surface finish quality of plastic molds. An integrated Value Stream Mapping (VSM) and Six Sigma DMAIC approach is applied to visualize end-to-end process flows (VA/NNVA/NVA), quantify performance gaps, analyze root causes (Fishbone with the 4M Man, Machine, Material, Method), and design improvements. VSM reveals three dominant wastes defects, inappropriate processing, and waiting linked to six critical failure causes spanning operator capability and discipline; overloaded schedules, equipment failures, machining errors, temperature control, and precision instability; material selection and procurement delays; and shortcomings in work- instruction compliance, machining parameters, drawing completeness, and standardized process flow. Using 5W+1H within DMAIC, the study proposes: standardized machining instructions and setup times; preventive- maintenance schedules and checklists; incoming verification with PIC accountability; structured training; mold quality checklists; weekly 5S/5R audits; and Future State Mapping to reduce NNVA/NVA. The integrated DMAIC–VSM roadmap is expected to shorten lead time, raise the value-added ratio, and improve surface finish quality, offering a transferable blueprint for similar manufacturing operations.

References

Ahmed, M., Haridy, S., Kaytbay, S., & Bhuiyan, N. (2019). Continuous improvement of injection moulding using Six Sigma: Case study. International Journal of Industrial and Systems Engineering, 32(2), 243–266.

Seham, I. S., As’arry, A., Sapuan, S. M., & Tarique, J. (2023). Improvement of plastic manufacturing processes by Six Sigma and DMAIC methods. Applied Science and Engineering Progress, 16(3), 6383.

Desai, D., & Prajapati, B. N. (2017). Competitive advantage through Six Sigma at plastic injection molded parts manufacturing unit: A case study. International Journal of Lean Six Sigma, 8(4), 411–435.

Jirasukprasert, P., Garza-Reyes, J. A., Kumar, V., & Lim, M. K. (2014). A Six Sigma and DMAIC application for the reduction of defects in a rubber gloves manufacturing process. International Journal of Lean Six Sigma, 5(1), 2–21.

Merjani, A., Yanti, P. P., & Redantan, D. (2023). Six Sigma DMAIC analysis to reduce visual reject on plastic raw materials in line IQC sorting using seven quality tools. Profisiensi, 11(1), 1–10.

Zulkarnaen, R. Z., & Widodo, K. H. (2023). Analisis pengurangan produk cacat menggunakan Six Sigma DMAIC di PT Trijaya Plastik Utama (Master’s thesis). Universitas Gadjah Mada.

Krist, P. G. (2017). Usulan perbaikan kualitas di CV. Jordan Plastics dengan metode Six Sigma DMAIC (Master’s thesis). Universitas Atma Jaya Yogyakarta.

Lean Enterprise Institute. (2023). Value stream mapping overview. Retrieved from https://www.lean.org/lexicon-terms/value-stream-mapping/

Six Sigma Online. (2023). DMAIC process: How to use it and an example. Retrieved from https://www.sixsigmaonline.org/dmaic-process-and-example/

Investopedia. (2010). What is Six Sigma? Concept, steps, examples, and certification. Retrieved from https://www.investopedia.com/terms/s/six-sigma.asp

Firdaus, A., Machfud, M., Suryani, A., & Achsani, N. A. (2019). Measuring Indonesia's energy security level in the context of biodiesel agroindustry. International Journal of Energy Economics and Policy, 9(6), 154-164.

Almahdy, I., Kholil, M., & Yasin, M. Y. (2018). A Case of Study on Correlation between Age, Noise Level, and Productivity at Barge in Oil Industry. In IOP Conference Series: Materials Science and Engineering, 453(1), 012009).

Rimawan, E., Kholil, M., & Fachira, S. (2019). Analysis quality control of garnish back door license in injection molding process using DMAIC method and VSM method at PT. Suzuki Indomobil Motor. Universal Journal of Mechanical Engineering, 7(6B), 19-31. https://doi.org/10.13189/ujme.2019.071504

Published

2025-09-30

How to Cite

Kholil, M., Hidayat, S., & Firdaus, A. (2025). Improving Surface Finish Quality of Plastic Molds via VSM and DMAIC Integration . Journal of Information System, Technology and Engineering, 3(3), 536–543. https://doi.org/10.61487/jiste.v3i3.187

Issue

Vol. 3 No. 3 (2025): JISTE

Section

Articles
Copyright & Licensing

Copyright (c) 2025 Muhammad Kholil, Syarif Hidayat, Alfa Firdaus

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.