For accurate fabrication of steel structures, shop drawings must be prepared prior to fabrication. This allows the contractor to identify any shortcomings or errors beforehand so that corrective action can be taken in time. When fabrication work is done without shop drawings, often problems are encountered during erection which is required to be rectified in the field leading to untidy work.
Modern shop drawing software allows users to model the entire structure in 3D which enables detection of any overlapping members. These software tools also generate the shop drawings for each member automatically once the 3D model has been created. This not only saves time but also minimizes chances of any human error in preparation of fabrication drawings.
Preparation of fabrication drawings is best done by such professionals who also have experience of working in a fabrication shop. This experience is very helpful in designing the critical connections and deciding other important aspects.