Economics of on-site vs off-site fabrication of rebar

Many contractors prefer on-site fabrication of rebar while others find that off-site fabrication is more advantageous. The economics of on-site and off-site fabrication of rebar need to be compared on the basis of several factors that include the project environment, wages, labour considerations, the initial investment for equipment, waste of rebar, the cost of inventory, cycle time, and supply chain management. This study presents an economic comparison of the on-site and off-site fabrication practices of rebar by means of a simulation model that makes use of the factors mentioned earlier. The model is populated with actual data obtained from a trade centre project in Istanbul, Turkey. The article indicates that the off-site fabrication practice would have been more costly than the on-site practice in the project in Istanbul, a finding that was to be expected in circumstances that prevail in most developing countries.