Abstract
Steel works, in a typical building project, consist of more than 20% of total construction cost, which makes it essential to estimate the appropriate level of steel works cost precisely. In order to draw direct labor productivity and indirect cost rates, theories of productivity and indirect cost were investigated, and recent field data were collected from steel factories. As a result, it was revealed that direct labor productivity of steel fabrication and welding were 1.00(person.day/ton), 0.35(person.day/ton), respectively. It was also found that the ratio of indirect labor productivity compared to the direct labor ratio was approximately 17% and the ratio of indirect cost compared to direct cost was approximately 93%. In addition, influence factor having an effect on indirect cost of the steel factories were analyzed using ANOVA. It was confirmed that 'the way of subcontracting steel works' and 'location of steel factory' had influence statistically on the indirect cost. The results will help industry professionals estimating labor productivity and indirect cost of a steel factory, as well as a construction project.