Buildings are made of beams, plates and angles. Norms can be flexible for agricultural buildings to very demanding for commercial buildings (rigour of traceability, authorized operations, etc.). Steel structure building projects are fabricated with some parts in stock, but mainly with parts to be ordered on demand. Revisions are frequent and it is necessary to know how to manage them. In order to optimize the use of steel, section and plate nesting are necessary, as well as the management of scraps to use them for future parts to be produced. Assemblies are numerous so welding stations are necessary and must be optimized to avoid bottlenecks. For example, all the parts of the same assembly must arrive at the same time on the assembly station, even though they come from a different machine with a different throughput. The tooling operations are very diverse: sawing, drilling, punching, milling, shearing, marking, scribing, Etc. The most common treatment is painting but galvanizing is sometimes necessary. The optimization of the shipments to the sites is a crucial point to optimize the costs.