All tasks related to the preparation of workshop drawings are done in the engineering department. After the design drawings are announced by the project owner, the engineering dept. study these drawings and controls all technical and engineering criteria and various standards. If there are any questions or ambiguities regarding the design drawings, these issues will be reflected in the form of technical query forms to the employer or the employer’s consultant. After clearing the ambiguity of the technical questions, these answers are considered in the preparation of the 3D model with Tekla software and the 3D model is finalized. In some projects where the employer or design consultant can control the 3D model, these models are sent to them and the necessary approval is obtained and then workshop drawings are prepared. In projects where it is not possible for the employer or the employer’s consultant to control the model, after completing the model, workshop drawings of steel structure are prepared and sent with the model to the employer to obtain their approval before production begins. After receiving approval from the employer, the output of Tekla software, including the list of assemblies, the list of single parts, etc., is entered in the PCIS (project control integrated software) software of SazvarSazeh Azarestan Company and in all stages of production from cutting to delivery and installation that software is used for preparing reports and progress of the projects.