Time study on two-echelon supply chain for steel framing construction: Field investigation and networking model simulation

This research presents a case study of how to apply the concepts of supply chain management (SCM) to the industry of structural steel construction. In this study the effects of scheduling and resources allocation were identified and examined by the following methodologies: (1) time study (2) linear regression models, and (3) networking simulation models.; This research work is primarily divided into three subsections. The first subsection, literature review, is to review and evaluate the current concepts of SCM in both manufacturing and construction industry. Throughout the literatures, it is evident that the theory of “multi-echelon inventory control” has been the essential issue in SCM in manufacturing. However, this research recommends the focus on the production (process flow) aspects for project-driven environment in construction.; The second subsection, echelon I—steel manufacturing, is to develop predictive models for estimating the “assembly hours” (ASM_HOUR) by using linear regression technique based on two significant variables: “total weights of steel” (PCKG_TON) and “pieces of steel” (PS_STEEL). The developed models were able to predict the schedule accurately for different structural design configurations: beams and columns, different building type. Furthermore, a simulation model was developed based on the time study of beams fabrication in steel shop. This model enables to show the different facets of productivity, scheduled utilization, and costing on different batch sizes.; The final subsection, echelon II—construction job site, is to develop CYCLONE simulation models based on time study of beams and columns erection of two case studies. This model simulated the entire erection process and evaluated the productivity and cost consumption of each task. The study showed that the project by using design-build (D/B) delivery had higher productivity and lower cost consumption than the project by using design-bid-build (D/B/B) delivery. Sensitivity analysis was also developed in this study and provided detail illustration of how productivity was affected by different resources allocation in steel erection construction. It indicated that by adding an extra resource of “crane” would dramatically increase the productivity in erection processes.