Application of Six Sigma Methodology in Ethiopian Building Construction Projects: A case in Adama Andode Village Residential Building construction Projects

Abstract

This study explores the application of Six Sigma methodology in Ethiopian building construction projects, with a specific focus on the Adama Andode Village residential building development. Despite global advancements in quality management, the Ethiopian construction sector continues to face persistent challenges related to defects, inefficiencies, and substandard project outcomes. To address these issues, this research applies the Six Sigma define, measure, analyze, improve, control framework to identify and reduce defects, improve process performance, and enhance construction quality. A mixed-methods approach was employed to collect and analyze data on construction defects before and after the implementation of improvement strategies. Results revealed a notable reduction in the total number of defects from 537 to 314 alongside an increase in yield by 12.47%. The calculated defects per million opportunities was 175,223.21, corresponding to a sigma level of approximately 2.46. While this demonstrates measurable improvements, the results remain below the industry benchmark of 3.0, signaling the need for continued process refinement. Further root cause analysis using fishbone diagrams identified key defect drivers such as inadequate supervision, poor communication, and weak management practices. These findings underscore the importance of addressing systemic organizational issues and enhancing stakeholder coordination. The framework developed is intended to guide contractors, consultants, and policymakers in systematically improving construction quality and reducing process inefficiencies. By integrating Six Sigma principles, the Ethiopian construction industry can advance toward achieving higher performance standards and sustainable project outcomes.