Girmay Kahssay (PhD)Gahsaw Kibru2025-05-142025-05-142025-02https://etd.aau.edu.et/handle/123456789/5452Lean Construction involves applying lean manufacturing principles, or lean thinking, to the construction industry with core concept of delivering the right things to the right place at the right time, in the right quantity, while minimizing waste and remaining adaptable to change. However, In Addis Ababa, lean implementation is still in its early stages, primarily relying on push planning systems and so far there is very few or no revealed study has been observed with regards of LC challenges. Thus, the main purpose of this study was to investigate the critical factors influencing the implementation of lean construction (LC) in building projects, focusing on four independent variables: Project Complexity, Management Support, Training and Education, and Cultural Attitudes. Convenience sampling was used to selecting a sample of 170 respondents from four selected construction companies in Addis Ababa and a structured questionnaire with a response rate of 95% was used to collect 160 valid data points. Descriptive research designs as well as a quantitative research approach were used to conduct the study. The Statistical Process for Social Sciences (SPSS version 27) was used to conduct statistical analyses. Utilizing regression analysis, the study reveals that all four variables exhibit significant positive associations with lean construction implementation, with correlation coefficients ranging from 0.659 to 0.719. Notably, Training and Education demonstrate the strongest relationship (0.719), followed by Management Support (0.705), Cultural Attitudes (0.684), and Project Complexity (0.659). The model fitness analysis indicates an R² value of 0.597, suggesting that approximately 59.7% of the variance in lean construction implementation is explained by these factors. However, 40.3% of the variance remains unexplained, indicating potential influences from other unexamined variables. The significance of the regression model, evidenced by an ANOVA significance value of 0.00, confirms its effectiveness in predicting the barriers to lean construction implementation. Standardized coefficients further reveal that Training and Education (Beta = 0.250) is the most influential factor, followed by Management Support (Beta = 0.236), Cultural Attitudes (Beta = 0.229), and Project Complexity (Beta = 0.181). These findings highlight the necessity of knowledge, skills, and management commitment in overcoming barriers to lean practices. The study emphasizes that a lack of training and awareness can hinder the effective application of lean methodologies, as noted in prior research. Management support emerged as a crucial element, with top management's commitment being vital for fostering a lean culture. Cultural attitudes were identified as barriers, wherein personal preferences and trust issues between management and employees can impede lean implementation. Additionally, the complexities associated with construction projects, including stakeholder interdependencies, pose significant challenges. In conclusion, the study identifies Training and Education, Management Support, Cultural Attitudes, and Project Complexity as key drivers in the successful adoption of lean construction. Recommendations for construction companies include investing in training programs, enhancing management support, fostering positive cultural attitudes, and effectively managing project complexities. By addressing these factors, construction firms can improve project efficiency, reduce waste, and ultimately enhance profitability and project delivery outcomes.en-USBuilding projectsLean constructionProject ComplexityManagement supportTraining & EducationCultural AttitudesAddis AbabaThesis