Identification of the Causes of Product Defects in the Screen-Printing Production Process Using Fault Tree Analysis (FTA) at PT. XYZ

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FORMOSA NEWS - Surakarta - Human Error Drives 78% of Defects in Screen-Printing Production, Study Finds. A high rate of product defects poses a significant challenge to operational efficiency and profitability in the screen-printing industry. A team of industrial engineering researchers from Universitas Duta Bangsa Surakarta—Sarif Hidayat, Brillian Nur Diansari, and Ringgo Ismoyo Buwono—conducted an in-depth investigation into the root causes of screen-printing failures at manufacturing firm PT. XYZ. Published in July 2026 in the Formosa Journal of Applied Sciences, the study analyzed production data from January to May 2026 to formulate targeted quality control strategies, revealing that human error is the single largest contributor to product defects.

The Cost of Quality Failures in Manufacturing
In modern manufacturing, maintaining rigorous quality standards is essential for preventing material waste, minimizing costly rework, and sustaining long-term market competitiveness. For screen-printing enterprises producing promotional media like sponsor banners, small variations in ink application or alignment can lead to widespread product rejection. At PT. XYZ, an operational audit spanning January through May 2026 revealed a substantial quality gap. Out of 26,940 total units produced, 2,532 units were classified as defective, representing an average defect rate of 9.4%. Because traditional quality management methods often address symptoms rather than underlying causes, the researchers sought a logical, data-driven framework to isolate systemic vulnerabilities.

Methodological Approach: Combining Pareto Analysis and Fault Tree Analysis
To identify and analyze the primary drivers of defective products, the research team from Universitas Duta Bangsa Surakarta applied a two-stage analytical framework:

• Pareto Analysis (80/20 Rule): The researchers categorized five distinct defect types recorded on the factory floor. By applying the Pareto principle, they isolated the vital few defect categories that accounted for approximately 80% of total product failures.
  
• Fault Tree Analysis (FTA): Using deductive logic tree structures with AND and OR logic gates, the team mapped the top failure events down to intermediate operational causes and basic root events. Occurrence probabilities were calculated for each basic event to pinpoint priority intervention points.
  

Data collection involved direct field observations, semi-structured interviews with screen-printing operators and quality control personnel, and an analysis of internal production records at PT. XYZ's facility in Sukoharjo Regency, Central Java.

Key Research Findings: Pinpointing the Root Cause
The initial Pareto analysis demonstrated that three dominant defect types accounted for a cumulative 78% of all defective products at PT. XYZ:

• Uneven Ink Application: Represented 35% of total defects (886 units).
• Ink Fading: Represented 25% of total defects (633 units).
  
• Print Position Error: Represented 18% of total defects (456 units).
  

The subsequent Fault Tree Analysis yielded top event failure probabilities of 0.81 (81%) for uneven ink, 0.63 (63%) for ink fading, and 0.79 (79%) for print position errors. Across all three top failure categories, human factors consistently emerged as the primary source of operational failure:

• Uneven Ink Causes: Human error contributed the highest sub-probability (0.41), driven primarily by operator carelessness (0.18) and incomplete process understanding (0.12). Machine issues, such as clogged screens (0.15), and environmental conditions, such as uneven table surfaces (0.07), acted as secondary factors.
  
• Ink Fading Causes: Human factors (0.24) and material factors (0.20) were the largest contributors. Key root causes included operator oversight during inspection (0.15), incorrect ink chemical composition (0.12), and insufficient curing temperatures (0.10).
  
• Print Position Error Causes: Operator error dominated with a sub-probability of 0.38, driven by general operator carelessness (0.16), fabric movement during printing (0.12), and misaligned material placement against registration markings (0.10). Loose clamping vices (0.11) also contributed to alignment shifts.
  

Industry Implications and Actionable Solutions
The findings of this research offer clear, practical guidance for small and medium-sized manufacturing enterprises (SMEs) seeking to improve quality assurance protocols. Based on the basic events with the highest failure probabilities, Sarif Hidayat and the research team outlined a comprehensive improvement framework structured around the 5M model (Man, Machine, Material, Method, Environment):

• Workforce Capacity Building: Implementing pre-production briefings, structured supervisory routines, and standardized operator training programs to reduce human error.
  
• Process Standardization: Establishing Standard Operating Procedures (SOPs) for precise ink mixing using calibrated measuring tools and installing physical position markings on printing tables.
  
• Preventive Equipment Maintenance: Routine cleaning and inspection schedules for kassa screens, clamping vices, and curing units to prevent mechanical breakdowns.
  
• Quality Control Check Sheets: Integrating multi-stage check sheets for pre-production setup, active production runs, and final product inspections to ensure documented quality compliance.
  

Author Profiles
Sarif Hidayat, S.T.: Principal researcher affiliated with the Department of Industrial Engineering, Faculty of Science and Technology, Universitas Duta Bangsa Surakarta. His research focuses on industrial quality control, statistical process management, and manufacturing optimization.
Brillian Nur Diansari, S.T., M.T.: Academic and researcher in Industrial Engineering at Universitas Duta Bangsa Surakarta, specializing in quality assurance systems, statistical quality control, and industrial operations management.
Ringgo Ismoyo Buwono, S.T., M.T.: Lecturer and researcher at the Faculty of Science and Technology, Universitas Duta Bangsa Surakarta, with expertise in work design engineering, ergonomics, and system reliability analysis.

Source
Sarif Hidayat, Brillian Nur Diansari, Ringgo Ismoyo Buwono. Identification of the Causes of Product Defects in the Screen-Printing Production Process Using Fault Tree Analysis (FTA) at PT. XYZ. Formosa Journal of Applied Sciences (FJAS), Vol. 5, No. 7, Tahun 2026, Hal. 1555–1566
DOI: https://doi.org/10.55927/fjas.v5i7.84
URL: https://journalfjas.my.id/index.php/fjas