If you're a welding contractor (fabricator, erector, or welding specialist) and you are working to contract drawings that specify an AWS welding code, then YOU NEED A WELDING PROCEDURE!
Don't worry, it's easy to do and most carbon steel welding is prequalified. Weldingprocedures.com specializes in procedures for AWS D1.1 Steel Welding Code used for structural steel buildings. If you are welding metals other than carbon steel, than you may need to qualify a procedure locally with a testing laboratory.