Analysis of Factors Contributing to Project Delays Using The Lean Six Sigma Approach

Delays in construction projects pose a major challenge, leading to inefficiencies in time, cost, and resource utilization. This research aims to identify the dominant factors contributing to project delays and propose effective mitigation strategies using the Lean Six Sigma framework. The research focuses on a refinery and wastewater treatment plant construction project in Sidoarjo, Indonesia, which experienced a nine-month delay due to improper planning, inadequate resource allocation, and misaligned project schedules. A mixed-method approach was applied, combining quantitative analysis through Likert-scale surveys and qualitative insights from expert interviews. The Lean Six Sigma methodology, particularly the DMAIC (Define, Measure, Analyze, Improve, Control) framework, was utilized to systematically diagnose delay factors and develop corrective actions. Key findings indicate that external variables such as late payments, extreme weather, and bureaucratic licensing issues significantly impact project timelines. Internal factors, including labor quality and ineffective communication, also contribute to delays. Through the Improve phase, Lean Construction techniques such as Value Stream Mapping and the Last Planner System were implemented, leading to a 30% reduction in project delays. These results highlight the effectiveness of Lean Six Sigma in optimizing construction project management. The research underscores the necessity of integrating structured risk management and process improvement strategies to enhance project efficiency and minimize future delays.