LEAN SIX SIGMA APPLICATIONS IN ELECTRICAL EQUIPMENT MANUFACTURING: A SYSTEMATIC LITERATURE REVIEW

Abstract

Lean Six Sigma (LSS) has emerged as a crucial methodology for improving process efficiency, defect reduction, and operational excellence in electrical equipment manufacturing. This study employs a case study approach, analyzing 30 case studies from transformer manufacturing, semiconductor and circuit board production, and multinational electrical manufacturers to evaluate the impact of LSS tools such as Define, Measure, Analyze, Improve, and Control (DMAIC), Value Stream Mapping (VSM), Statistical Process Control (SPC), and Failure Mode and Effects Analysis (FMEA). The findings demonstrate that LSS implementation leads to a 35% reduction in defect rates, a 40% increase in product reliability, and a 30% improvement in first-pass yield rates, reinforcing its effectiveness in optimizing manufacturing processes. Additionally, the study highlights the transformative role of Industry 4.0 technologies, including IoT-enabled predictive maintenance, AI-driven defect detection, cyber-physical systems, and real-time analytics, which further enhance Six Sigma capabilities by enabling automated quality monitoring and proactive process adjustments. The integration of robotic process automation (RPA) and cloud-based manufacturing execution systems (MES) has resulted in a 50% increase in defect detection accuracy and a 45% reduction in unexpected equipment failures, illustrating the synergy between LSS and digital transformation. However, challenges such as organizational resistance, workforce engagement, and inconsistent leadership commitment hinder successful LSS adoption. The study finds that companies with structured Six Sigma training programs and active executive support experience 40% more successful defect reduction outcomes than those with passive leadership involvement. Ultimately, the research underscores that Lean Six Sigma, when strategically integrated with Industry 4.0 innovations and embedded as a long-term operational framework, delivers sustainable improvements in product quality, manufacturing efficiency, and cost-effectiveness in electrical equipment production.