Steel structures are made of girders, plates and angles, but also of welded beams for bridges for example. The norms for this type of projects are very demanding and therefore require precise and reliable monitoring of the material and the production processes. Inventory management must be very rigorous because the slightest error can lead to considerable costs, given the size of the profiles to be ordered. In addition, the necessary parts are rarer, so orders must be largely anticipated to avoid production delays. The tooling operations are complex and varied: they are the same as for the fabrication of buildings, to which must be added the cutting of very thick plates, the bending of very long and voluminous profiles that will also require drilling operations, the cutting and welding of voluminous plates that will make up the welded beams, the milling of profiles and plates to prepare for welding operations, etc. Welding operations are often demanding and require qualified and certified employees. Punching is often forbidden for this type of work because it is an operation that weakens the material and the norms do not tolerate it. All projects are unique and therefore there is no standardization dimension for this type of work. The treatments are generally painting and more rarely galvanizing. Loads are complex to manage because the items are often voluminous and require special organization for delivery such as exceptional shipments.