The annual production capacity of Heavy Steel Structures of Esfahan Machinery Manufacturing Company (EMMC) is 15,000 tons. Cutting, beam making, assembly, welding and cleaning operations, and finally sandblasting and paint are the main activities of Steel Structures production activities, all of which are built-in 13 roofed halls with an area of 20,000 square meters. If needed there are 18,000 square meters of workshop space which is equipped with overhead cranes. In order to speed up the painting operation, a painting hall with an area of 1600 square meters equipped with twenty blowers and air suckers has been set up. Sheet-making machines, CNC cutting machines, scissors, three-axis drills, semi-automatic submerged arc welding, CO2, and plate processing are used in the process of making steel structures. Before starting the manufacturing process, the drawings are converted to a three-dimensional model in various software, including Tekla, and then the workshop and construction drawings are extracted from this model. All construction stages are based on the plans of the production planning unit and in accordance with the approved manufacturing instructions and relevant standards, and the QC unit supervises its proper execution.