Abstract
Construction is a labour-intensive industry. As poor productivity of construction labour is one of the causes of cost and time overruns in construction projects, it is of critical importance to the performance and profitability of construction projects and the overall economy of any country. This paper aimed to identify and rank factors affecting construction labour productivity in Yemen. A survey questionnaire was structured and distributed to architectural and structural engineers who were working on construction projects. The questionnaire included 52 predefined factors, which were categorized into four primary groups: human/labour, management, technical and technological, and external. The relative importance index (RII) was determined and the factors were ranked. The results showed that the group of technical and technological factors ranked first among the four groups. The top five factors identified were the most significant in their effect on construction labour productivity in Yemen: (1) labour's experience and skills, (2) availability of materials in site, (3) leadership and efficiency in site management, (4) availability of materials in the market, and (5) political and security situation. The findings of this study will provide awareness and a better understanding of factors affecting labour productivity in construction projects in Yemen.