Title: Six Sigma-Based Quality Improvement in Aerospace Component Assembly- The Case of PT SkyInnovate Indonesia
Authors: Naniek Utami Handayani and Huda Brilian
Volume: 9
Issue: 10
Pages: 196-210
Publication Date: 2025/10/28
Abstract:
This study investigates the application of the Six Sigma DMAIC (Define-Measure-Analyze-Improve-Control) methodology to enhance product quality and reduce nonconforming occurrences in the Tail Boom Assembly process at PT SkyInnovate Indonesia, an aerospace manufacturing company operating within a developing-country context. The research aims to identify the dominant causes of defects, evaluate process capability, and propose structured improvement actions to achieve higher process performance. A case study design was adopted, combining quantitative and qualitative analyses based on production and quality assurance data from the 2023 manufacturing cycle. Using the DMAIC framework, the study applied statistical tools including control charts, Pareto analysis, and fishbone diagrams to identify, quantify, and prioritize sources of nonconformance. The analysis revealed a process sigma level of approximately 3.5 with a Defects per Million Opportunities (DPMO) value of 22,772.28, indicating moderate capability relative to global aerospace benchmarks of 4.5-5.5 sigma. Pareto analysis showed that scrap and rework accounted for 96% of total defects, while root-cause analysis identified measurement inaccuracies, procedural inconsistencies, and operator skill variability as dominant contributors. Proposed improvement actions included implementing measurement system analysis, standardizing work procedures, enhancing operator training, and instituting preventive maintenance. The findings demonstrate that applying Six Sigma in aerospace subassembly manufacturing effectively identifies systemic weaknesses and provides data-driven improvement strategies. Although the process has not yet reached world-class performance, the structured use of DMAIC has established a foundation for continuous improvement and operational discipline. The study highlights the potential for incremental sigma improvement through sustained quality initiatives and organizational learning. These results contribute to the growing body of literature on Six Sigma implementation in developing economies and provide practical insights for aerospace manufacturers seeking to enhance process reliability and competitiveness.