Process Optimization Using Six Sigma Strategy in Garment Manufacturing: A Case from Vietnam

The garment industry in Vietnam is under scrutiny from global competitors and consumers looking for high quality but at a reasonable cost [1]. Although the garment industry performs an important role in Vietnam’s economy and its international integration, there are challenges, (such as: inefficiencies in production, i.e., cutting) the use of fabric is a costly element of producing an apparel item and large amounts of waste can lead to higher production costs and less customer satisfaction. Although Six Sigma programmes have been popular in other industries, not so much attention has been given to garment manufacturing yet despite exhaustive support of structured program definitions [2].

The aim of the study

This study looks into the potential of utilizing the DMAIC framework of Six Sigma in an effort to optimize the cutting process for a well-known Vietnam garment company (Vinatex) [3]. It will be looking to eliminate defects, assist the company and employees in operating efficiently and standardize work practices in a labor-intensive environment [4].

Research questions

A. What is the impact of Six Sigma on defects in garment manufacturing?
B. What operational issues arise when implementing Six Sigma in the textile industry?
C. What efficiency gains (if any) result from this intervention?

Data was collected from the DMAIC (Define, Measure, Analyze, Improve, Control) methodology [5].
A. Define: The CTQ analysis outlined the primary contributors to quality issues (pile mismatch, mislabeling, tension loss).
B. Measure: Data was compiled in a 30-day duration. Process capability was assessed through P-charts and images of the histograms were completed.
C. Analyze: The root causes were determined using Pareto analysis combined with a cause and effect (fishbone) diagram.
D. Improve: Targeted solutions were employed, including automated tension controllers, operator retraining, machine calibration, and a cooler code system.
E. Control: Standard Operating Procedures were put in place, visual dashboards implemented, poka-yoke mechanisms were constructed, SPC developed and bi-weekly refresher training established for operators to ensure the procedural changes would be sustainable.

Defect rate decreased 61.5% (26% to 10%).
Reduced machine downtime 66.7%
Reduced product reworks 55.6%
Operator training assessments increased by 38.5%
Measurement accuracy improved by 25%
Process efficiencies improved 25.7%

The findings from the above developments clearly show an overall reduction in defects along with an overall improvement in efficiency and process capabilities with the workforce as a result of implementing Six Sigma in the garment sector.

The introduction of Six Sigma provided a clear reduction in defects, thus demonstrating its effectiveness to the garment manufacturing setting. It was indicated defect rates were reduced overall by an impressive 61.5% and clearly structured process pattern control that can lead to improvement in quality [5]. The key operational challenges during Six Sigma application included variability of fabric tension during processes, skill capacity for operators, and inspection for machine adjustment [6]. This was achieved through focus training, automated controls, and standardized operating instruction. The measurable gain reported through Six Sigma included 66.7% reduction in Machine Downtime, 55.6% reduced Product Rework, and improved Process Efficiency by 25.7%; also, absorbed in the operator training score improved by 38.5%, which will allow sustainability in the long run. Overall, with these results it confirms the application of Six Sigma can be utilized in the textile industry, consistent with its findings in other industrial sectors, as well as scale the business model to incorporate successfully in a small family business.

This study:
A. Provides one of the first practical applications of Six Sigma to large scale Vietnam garment manufacture.
B. Illustrates a data-driven, sustainable and replicable model, to aid with defect reduction and quality improvement.
C. Imparts scalable recommendations directly to textile manufacturers considering operational excellence globally.

The study validated Six Sigma’s DMAIC tool for a reduction of defects and improving efficiency for garment manufacture specifically with the cutting process at Vinatex. The study not only identified root causes related to fabric misalignment, mislabeling, and tension variation and had specific interventions, but the overall study led to a 61.5% reduction in defects and a 66.7% reduction in downtime for machines to complete their phase of the cutting process. Increased measurement accuracy and improvements in operating behaviour were noted along the way. The structured and systematic approach introduced improvements in not only product quality, but also implementing controls, in order for Vinatex to have sustainable controls. Therefore, the findings indicate that a Six Sigma approach can be adapted successfully in laborintensive environments like textiles, while also contributing to a sustainable process that can be used as a foundation for continuous improvement of the garment manufacturing industry.

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2. Lin CWR, Lai YS, Jeng SY, Nguyen TTV, Lim MK (2025) Supply chain disruption indicators: vulnerability and resilience in the garment industry in Vietnam. Cleaner and Responsible Consumption 16: 100251.
3. Taylor JK (2018) Quality assurance of chemical measurements. Routledge, UK.
4. Sharma A, Singh BJ (2023) Evolution of modified LSS 4.0 model for sustainable Indian textile industry: A narrative review. International Journal on Interactive Design and Manufacturing (IJIDeM) pp: 1-20.
5. Saad H (2020) The application of data mining in the production processes. arXiv preprint arXiv:2011.12348.
6. Keane J, Velde DWT (2008) The role of textile and clothing industries in growth and development strategies.