To qualify a welding technology, it is required to weld and test the quality of the experimental fittings under the supervision of a notified body. All activities are conducted under the following series of norms: PN-EN ISO 15614, PN-EN ISO 15614-1 (for steel), PN-EN ISO 15614-2 (for aluminum). Before the examination, a presentation of the experimental fittings is required in order to establish and prepare Pre-Welding Procedure Specifications (pWPS) which are devised by a welding engineer. Obtaining the WPQR certificate issued by the notified body enables the company to construct welded aluminum structures, which construction is supervised by the legally asigned bodies or by institutions asigned by the investor. The company possesses welding qualifications (i.e. the welding method, the type of materials welded, the thickness of welded materials, etc.) which are stated in the issued WPQR certificate. Every single material requires a seperate welding technology qualification for each welding method utilized in the company and for other welding process variables.