الخلاصة

Productivity is a very important element in the estimation process in construction management. The objective of this research is to identify and analyze the factors which effect on labor productivity in construction projects. In this research, 42 effective factors were collected from site survey, interviewing with engineers and experts, and previous research in the Arab world. These factors are grouped into Nine categories "Workforce, Leadership, Motivation, Supervisors, Safety, Project, Time, Material, and External". A questionnaire survey of 70 respondents was distributed among different experts. A statistical Analysis was done using SPSS and EXCEL packages. The relative importance index was used to find out the most significant factors affecting the labor productivity in construction sites. The results accomplished from the survey revealed that the major factors negatively effect on the labor productivity (ranked from the worst factor with relative importance index values respectively) namely, Availability Material (88.571%), Climate status "Weather" (88%), Religious occasions (86.29%), Number of working groups (86%), Ganger experience (85.714%), Workforce surveillance (84.857%), Ganger Age (84%), working at high place (82%), Drawings and specifications alteration during execution (81.69%), and Sequence of floor (80.571%). Based upon these findings, this can help the construction professionals to improve the productivity and project performance in Iraq.