Depending on the Code involved, the company has to sign them to take responsibility for them.  You can use the approved ones right out ot the box.  But if you don't have experience using the process involved, you will not be able to easily use one of these Standard WPSs using the parameters stated on the WPS,  They are full range parameters, and most experienced welders have favored settings, that give them the best results. If those favored settings do not fall into the parameter limits set on the Standard WPS, the welder must make the appropriate adjustments.